Chapter 19 - What Happens When You Start Your Computer
This chapter describes what happens when you start a computer that has a Windows NT installed as one of the operating systems. In general, this chapter describes what happens at each step in the process when the computer successfully starts. Chapter 21, "Troubleshooting Startup and Disk Problems," discusses what you can do to isolate startup problems, and how to recover from them.
This chapter also describes dual-booting and triple-booting other operating systems, such as Windows 95 and MS-DOS. It provides information about the contents of the Boot.ini file on x86-based computers, and describes the firmware menus and how to use them on RISC-based computers.
Starting Windows NT
This section describes the steps involved in the successful startup of Windows NT, which are the following:
The order and the processing is somewhat different, depending upon the hardware platform (x86-based computer or RISC-based computer).
The startup process begins when you:
When you see the Begin Logon dialog box, with the text Press Ctrl+Alt+Delete to log on, your computer has completed the loading of Windows NT, and has completed much of the initialization. However, startup is complete only when a user can successfully log on at the Begin Logon dialog box.
Windows NT might not start up or operate correctly if any hardware components do not initialize correctly. Startup fails if any of the files required to start Windows NT are not present in the correct folder, or if one of the files has been corrupted. Table 19.1 describes the files that x86-based computers and RISC-based computers use to start Windows NT.
Power On Self Test Processing
When you power on or restart a computer, it goes through its Power On Self Test (POST) routine, which determines:
Once the computer has run its POST routine, each adapter card with a BIOS runs its own POST routine. The computer and adapter card manufacturers determine what appears on the screen during the POST processing.
Initial Startup Process
The first sector on the hard disk is critical to the startup process. This sector contains the Master Boot Record and the Partition Table.
If the startup disk is a floppy disk, the first sector on the disk is the Partition Boot Sector.
For more information about the Master Boot Record, the system partition, and the Partition Boot Sector, see Chapter 17, "Disk and File System Basics."
Starting an x86-based Computer
After the POST on x86-based computers, the system BIOS attempts to locate the startup disk. If there is a floppy disk in drive A, the system BIOS uses drive A as the startup disk. If there is no disk in drive A, the system BIOS then checks the first hard disk that is powered up.
Note Some system BIOS versions enable the user to reconfigure the order in which it checks the floppy disks and hard disks for the startup disk.
When the hard disk is the startup disk, the system BIOS reads the Master Boot Record, and loads it into memory. The system BIOS then transfers execution to the Master Boot Record. The code in the Master Boot Record scans the Partition Table for the system partition. When the Master Boot Record finds the system partition, it loads sector 0 of the partition into memory, and executes it. Sector 0 on the system partition can be a utility or diagnostic program, or a Partition Boot Sector that contains startup code for an operating system. The Partition Boot Sector code starts the operating system in a manner defined by the operating system.
If there is no system partition on the first hard disk, the Master Boot Record displays errors such as the following:
The section "Setting the System Partition (x86-based Computers)," presented later in this chapter, describes identifying and changing the system partition.
The Master Boot Record is generally operating system independent. For example, on x86-based computers, you use the same Master Boot Record to start Windows NT, Windows 95, MS-DOS, and Windows 3.1x.
However, the Partition Boot Sector is dependent on both the operating system and the file system. On x86-based computers, the Windows NT Partition Boot Sector is responsible for:
On x86-based computers, the system partition must be on the first physical hard disk. The boot partition (the partition containing Windows NT operating system files) can be the same as the system partition, can be on a different partition on the same hard disk, or can even be on a different hard disk.
If the first hard disk does not contain the system partition that you want to use to start your computer, you need to power down the disk so that the system BIOS can access the correct disk.
For information about why you might want to use another hard disk as your startup disk, see Chapter 20, "Preparing for and Performing Recovery."
If there is a floppy disk in drive A, the system BIOS loads the first sector on the disk into memory. If the floppy is bootable, the first sector on the disk is the Partition Boot Sector. If the floppy disk is not bootable, you see errors such as:
Non-System disk or disk error Replace and press any key when ready
Starting a RISC-based Computer
After a RISC-based computer completes the POST routine, the resident ROM firmware selects the startup disk by reading a boot precedence table from nonvolatile RAM (NVRAM). What the firmware does depends upon the platform (Alpha, PowerPC, or MIPS computer) and the information in the NVRAM. For example, to startup from the floppy disk, the NVRAM must define it as an alternate boot selection.
The NVRAM also defines the:
The system partition can be on any hard disk on RISC-based computers. You can use the Boot selection menu to set up or change the system partition. See "Manage Boot Selection Menu," presented later in this chapter, for more information about changing the firmware and NVRAM on RISC-based computers.
The system partition on a RISC-based computer must be formatted with the FAT file system. This is because the ARC standard requires that firmware have the following stub drivers built into it:
RISC-based computers go straight from the firmware into OSLOADER, which is the RISC-based computer's equivalent of NTLDR. Therefore, the firmware has to take over the functionality of the Partition Boot Sector, which means that the partition that has OSLOADER on it has to be FAT. Once OSLOADER loads, it has enough of the NTFS drivers built into it (just like NTLDR does) that it can access a %systemroot% folder on an NTFS partition.
Setting the System Partition (x86-based Computers)
On an x86-based computer, the system partition must contain the boot loader and other files that load the operating system. Windows NT Setup sets the partition into which it installs these files as the system partition, but there are situations in which you might want to use another.
When Windows NT is running, you can use Disk Administrator to set the system partition. You can also use the MS-DOS-based utility Fdisk to set the system partition. Only a primary partition can be used as a system partition. You cannot use a logical drive in the extended partition as a system partition. When you set a new system partition, both Disk Administrator and Fdisk clear the Boot Indicator field, if it was set for any other partition.
Note The Boot Indicator field in the Partition Table indicates whether a partition is the system partition.
To Use Disk Administrator to set the system partition
You cannot use Disk Administrator to set the system partition if you cannot start Windows NT. You can use the MS-DOS-based Fdisk utility to set the system partition, even if your entire disk is formatted with the NTFS file system.
To Use the Fdisk utility
Boot Loader Process
The boot loader enables you to select the operating system that you want to start, and loads the operating system files from the boot partition. Boot loader processing is different on x86-based and RISC-based computers.
NTLDR Functions (x86-based Computer)
NTLDR controls the operating system selection process and hardware detection prior to the Windows NT Kernel initialization. NTLDR must be in the root folder of your startup disk, and also requires that the following files be located in the root folder:
If the path name in the Boot.ini file for your system partition uses the scsi() syntax, the file Ntbootdd.sys must be in the root folder of the system partition. For more information about the scsi() syntax and Ntbootdd.sys, see Chapter 20, "Preparing for and Performing Recovery."
When NTLDR starts executing, it clears the screen and displays the boot loader message, which is:
OS Loader V4.0
NTLDR then performs the following steps:
OSLOADER Functions (RISC-based Computers)
On RISC-based computers, Osloader.exe performs all of the functions that are performed by the x86-based components NTLDR, Ntdetect.com, and Bootsect.dos.
The NVRAM contains environment variables that provide the functional equivalent of the Boot.ini file on x86-based computers.
Selecting the Operating System to Start
The boot loader displays the screen from which you select the operating system to start. The information on the screen is different for x86-based computers and RISC-based computers.
Boot Loader Screen (x86-based Computer)
NTLDR displays a menu from which you select the operating system to start. This screen is based upon the information in the Boot.ini file. The screen looks like this:
OS Loader V4.0 Please select the operating system to start: Windows NT Workstation Version 4.0 Windows NT Workstation Version 4.0 (VGA mode) MS-DOS Use [up] and [down] to move the highlight to your choice. Press Enter to choose. Seconds until highlighted choice will be started automatically: 29
If you do not select an entry before the counter reaches zero, NTLDR loads the operating system specified by the default parameter in the Boot.ini file. Windows NT Setup sets the default entry to the most recent copy of Windows NT that you installed. You can edit the Boot.ini file to change the default entry if you want to default to an operating system other than the most recently installed version of Windows NT.
For information about changing the Boot.ini file, see "Contents and Purpose of Boot.ini," presented later in this chapter.
Boot Menu (RISC-based Computers)
The Boot menu contains the boot options. The first selection is always the default operating system, which is the most recently installed version of Windows NT unless you change the order of the boot selections.
To change the default operating system, or add or change boot selections , see the section titled "Manage Boot Selection Menu," presented later in this chapter.
This is a sample Boot menu from an Alpha-based computer:
ARC Multiboot Alpha AXP Version 3.5-11 Copyright (c) 1993 Microsoft Corporation Copyright (c) 1993 Digital Equipment Corporation Boot Menu: Boot Windows NT Workstation Version 4.0 Boot an alternate operating system Run a program Supplementary menu. . . Use the arrow keys to select, then press Enter. Seconds until auto-boot. Select another option to override: 9
The first line on the Boot menu is highlighted. Pressing ENTER begins startup of the default operating system.
If you have included alternate boot selections in your NVRAM, you can select Boot an alternate operating system, which results in a screen like the following.
ARC Multiboot Alpha AXP Version 3.5-11 Copyright (c) 1993 Microsoft Corporation Copyright (c) 1993 Digital Equipment Corporation Boot Menu: Boot Windows NT Workstation 4.0 (Default) Boot Windows NT Workstation 3.51 Boot SCO Unix v7.2 Use the arrow keys to select, then press Enter.
On RISC-based computers, Osloader.exe obtains the hardware information from the firmware.
Ntdetect.com is the hardware detector for x86-based computers. It collects a list of currently installed components and returns this information to NTLDR.
On x86-based computers, Ntdetect.com executes after you select a Windows NT operating system on the boot loader screen (or the timer times out). When Ntdetect.com begins to execute, you see the following line on the screen:
NTDETECT V1.0 Checking Hardware . . .
Ntdetect.com detects the following components:
Selecting a Configuration
When you have selected the version of Windows NT to start, and the boot loader has collected hardware information, you see the following screen:
OS Loader V4.0 Press spacebar now to invoke Hardware Profile/Last Known Good menu.
The boot loader waits a few seconds for you to press the SPACEBAR. If you do not press the SPACEBAR, and you have only one hardware profile, the boot loader loads Windows NT by using the Default control set. Otherwise, you see this screen:
Hardware Profile/Configuration Recovery Menu This menu allows you to select a hardware profile to be used when Windows NT is started. If your system is not starting correctly, then you may switch to a previous system configuration, which may overcome startup problems. IMPORTANT: System configuration changes made since the last successful startup will be discarded. Original Configuration some other hardware profile Use the up and down arrow keys to move the highlight to the selection you want. Then press ENTER. To switch to the Last Known Good Configuration, press 'L'. To Exit this menu and restart your computer. press F3. Seconds until highlighted choice will be started automatically: 5
The first hardware profile is highlighted. If you have created other hardware profiles, use the down arrow to select the one that you want to use. For more information about hardware profiles, use the Find tab in Windows NT Help and enter profile.
You can also select between the Last Known Good Configuration and the Default Configuration. Windows NT automatically uses the Default Configuration if you do not select the Last Known Good Configuration. When you use the Default Configuration, the boot loader uses the Registry information that Windows NT saved at the last shutdown.
If you switch to the Last Known Good Configuration by pressing L and ENTER, the boot loader uses the Registry information that it saved at the completion of the last successful startup to configure this startup.
See the sections "Loading the Kernel" and "Control Sets in the Registry," presented later in this chapter, for more information.
Loading the Kernel
When you press ENTER on the Hardware Profile/Configuration Recovery menu or the boot loader automatically makes the selection for you, the computer is in the Kernel load phase of Windows NT startup. You see several dots as the boot loader loads the Windows NT Kernel (Ntoskrnl.exe) and the hardware adaption layer (Hal.dll) into memory. It does not initialize these programs yet. Next, the boot loader loads the Registry key HKEY_LOCAL_MACHINE \SYSTEM from %systemroot%\System32\Config\System.
At this point, the boot loader creates the control set it will use to initialize the computer. The value in the HKEY_LOCAL_MACHINE \SYSTEM \Select subkey determines which control set in HKEY_LOCAL_MACHINE \SYSTEM to use. The loader uses the control set identified by the Default value, unless you are starting by using the Last Known Good Configuration. In this case, the value under LastKnownGood specifies the control set. Based on your selection and the value of the corresponding Select subkey, the loader determines which ControlSet00x to use. It sets the value of Current in the Select subkey to the number of the control set it will use.
See "Control Sets in the Registry," presented later in this chapter, for more information about the Select subkey and control sets.
At this time, the boot loader scans all of the services in the Registry subkey HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet \Services for device drivers with a Start value of 0x0, which indicates that they should be loaded but not initialized. Device drivers with these values are typically low-level hardware device drivers, such as hard disk device drivers. The Group value for each device driver determines the order in which the boot loader loads them. The Registry subkey HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet \Control ServiceGroupOrder defines the loading order.
On x86-based computers, the loading of these device drivers into memory is done using BIOS INT 13 calls in real mode (or by Ntbootdd.sys).
On RISC-based computers, OSLOADER calls firmware primitives to find and load the critical files into memory.
The Windows NT Workstation Resource Kit CD contains more information about the Registry in the Help file Regentry.hlp. When you install the Resource Kit, double-clicking the Registry Help File icon opens the Regentry.hlp.
Initializing the Kernel
You know that the Kernel is initializing when the screen turns blue, and you see text similar to the following:
Microsoft (R) Windows NT (TM) Version 4.0 (Build 1345) 1 System Processor (16 MB Memory)
This means that Ntoskrnl.exe has successfully initialized and that control has passed to it.
The Kernel creates the HKEY_LOCAL_MACHINE \HARDWARE key by using the information that was passed from the boot loader. This key contains the hardware data that is computed at each system startup. The data include information about hardware components on the system board and about the interrupts hooked by specific hardware devices.
The Kernel creates the Clone control set by making a copy of the control set pointed to by the value of Current. The Clone control set is never modified, because it is intended to be an identical copy of the data used to configure the computer and should not reflect any changes made during the startup process.
Loading and Initializing Device Drivers
The Kernel now initializes the low-level device drivers that were loaded during the Kernel load phase. If an error occurs, the action taken is based on the HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet \ServicesDriverName\ErrorControl value for the device driver that has a problem. See the section titled "ErrorControl Values," presented later in this chapter, for more information.
Ntoskrnl.exe now scans the Registry, this time for device drivers that have a HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet \ServicesDriverName\Start value of 0x1. As in the Kernel load phase, the Group value for each device driver determines the order in which they are loaded. The Registry subkey HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet \Control \ServiceGroupOrder defines the loading order.
Unlike the Kernel load phase, device drivers with a Start value of 0x01 are not loaded by using BIOS or firmware calls, but by using the device drivers loaded during the Kernel load phase and just initialized. The device drivers in this second group are initialized as soon as they are loaded. Error processing for the initialization of this group of device drivers is also based on the value of the ErrorControl data item for the device driver.
The section titled "Start Values," presented later in this chapter, contains more information about when components are loaded and started.
The Session Manager (Smss.exe) starts the higher-order subsystems and services for Windows NT. Information for the Session Manager is in HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet \Control \Session Manager. Session Manager executes the instructions under the:
BootExecute Data Item
The BootExecute data item contains one or more commands that Session Manager runs before it loads any services. The default value for this item is Autochk.exe, which is the Windows NT version of Chkdsk.exe. The default setting is shown in this example:
BootExecute : REG_MULTI_SZ : autocheck autochk*
Session Manager can run more than one program. This example shows the item when the Convert utility will be run to convert the x volume from FAT to NTFS on the next system startup:
BootExecute : REG_MULTI_SZ : autocheck autochk* autoconv \DosDevices\x: /FS:ntfs
After Session Manager runs the commands, the Kernel loads the other Registry keys from %systemroot%\System32\Config.
Memory Management Key
Next, the Session Manager creates the paging information required by the Virtual Memory Manager. The configuration information is located in these data items:
PagedPoolSize : REG_DWORD 0 NonPagedPoolSize : REG_DWORD 0 PagingFiles : REG_MULTI_SZ : c:\pagefile.sys 32
For information about the page file, use the Index tab in Windows NT Help, and enter virtual memory.
DOS Devices Key
Next, the Session Manager creates symbolic links. These links direct certain classes of commands to the correct component in the file system. The configuration information for these default items is located in:
PRN : REG_SZ : \DosDevices\LPT1 AUX : REG_SZ : \DosDevices\COM1 NUL : REG_SZ : \Device\Null UNC : REG_SZ : \Device\Mup PIPE : REG_SZ : \Device\NamedPipe MAILSLOT : REG_SZ : \Device\MailSlot
Because of the messaging architecture of subsystems, the Windows subsystem (Win32) must be started. This subsystem controls all I/O and access to the video screen. The process name for this subsystem is CSRSS. The Windows subsystem starts the WinLogon process, which then starts several other vital subsystems.
The configuration information for required subsystems is defined by the value for Required in the Registry subkey HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet \Control \Session Manager\SubSystems.
The Windows subsystem automatically starts Winlogon.exe, and Winlogon.exe starts the Local Security Administration (Lsass.exe). You now see the Begin Logon dialog box, which contains the text Press Ctrl+Alt+Delete to log on. At this time, Windows NT might still be initializing network device drivers, but you can logon now.
Next the Service Controller (Screg.exe) executes, which makes a final pass through the Registry looking for services that are marked to load automatically. Auto-load services have a Start value of 0x2 in the subkeys HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet \ServicesDriverName.The services that are loaded during this phase are loaded based on their dependencies, because they are loaded in parallel. The dependencies are described in the DependOnGroup and DependOnService entries in the subkey HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet \ServicesDriverName.
Note Windows NT startup is not considered good until a user successfully logs on to the system. After a successful logon, the Clone control set is copied to the LastKnownGood control set.
Configuring the Computer for Dual-booting and Triple-booting
This section describes how to start up multiple operating systems and contains procedures for configuring your computer to do so.
Each operating system uses one or more file systems to organize data within volumes. Some operating systems can use the same file systems and some can not. For example, MS-DOS, Windows 95, and Windows NT can each use FAT volumes; Windows NT and Unix each use file systems that are unusable by the other. Operating systems that use the same file systems can share volumes, meaning that a user can access files on these volumes when running any of the operating systems.
Note Create an Emergency Repair Disk for your Windows NT installation by using the Repair Disk utility (Rdisk.exe) in the %systemroot%\System32 folder before you install other operating systems on the computer. You should also have a Windows NT startup floppy disk that you know works to start your computer. For more information about these disks, see Chapter 20, "Preparing for and Performing Recovery."
Using More Than One Windows Operating System
Windows 95, Windows 3.1, or Windows 3.11 can reside on the same computer as Windows NT. Windows NT can be installed in the same folder as Windows 3.1 or Windows 3.11 because Windows NT puts all of its important files in the system32 folder. Windows NT only uses the %systemroot% folder for legacy ini files that it maintains for 16-bit application programs and backwards compatibility. So, all of the Windows 3.1 or Windows 3.11 files will be either in the %systemroot% folder or in the %systemroot%\System folder. This organization allows the two operating systems to co-exist in the same folder.
You can also install Windows NT into a different folder. Windows 3.1 or Windows 3.11 still co-exist with Windows NT, but you do not get the option to migrate ini and program manager settings from Windows 3.1 or Windows 3.11.
If you install Windows 95 and Windows NT on the same disk, you must install them in different folders.
You can also install different versions of the Windows NT operating system on your hard disk, as long as you install them on different folders. If you are going to log into a domain, each instance of Windows NT must have a different computer name, which you specify during Windows NT Setup. You should ask your network administrator for the computer name to use before running Windows NT Setup.
When you install multiple Windows operating systems on the same computer, you need to install Windows-based application programs by using each operating system. For example, if you install both Windows 95 and Windows NT 4.0, you need to install application programs when you are running Windows NT 4.0 and when you are running Windows 95. If you have more than one version of Windows NT installed, you also need to install the application programs when running each version. To install Windows-based application programs when running Windows NT 4.0, you must log on with a user ID that has administrative privileges.
Dual-booting on x86-based Computers
When your system partition contains the Windows NT Partition Boot Sector, Windows NT supports dual-booting between one or more instances of Windows NT and one additional operating system. The additional operating systems that are currently supported are MS-DOS, Windows 95, and OS/2, versions 1.1 and 1.3. OS/2 versions 2.x might work, but are not supported.
You can also triple-boot Windows NT, Windows 95, and MS-DOS. You can install and start up other operating systems from your hard disk, but you need to change the system partition. For procedures to change the system partition, see "Setting the System Partition," presented earlier in this chapter.
When you install a Windows NT operating system on an x86-based computer, Windows NT Setup copies the first sector of the system partition (the Partition Boot Sector) to a file named Bootsect.dos. It then replaces the Partition Boot Sector with its own Partition Boot Sector.
When you start your computer and the system partition contains the Windows NT Partition Boot Sector, the code in the Partition Boot Sector loads the Windows NT boot loader, NTLDR. The boot loader screen enables you to choose which Windows NT installation to start, or to start another operating system that is defined on the boot loader screen.
If you select an operating system other than Windows NT from the boot loader screen, NTLDR loads and starts the Bootsect.dos file. This functionality results in the other operating system starting as if NTLDR had not intervened. In the case of MS-DOS, the Bootsect.dos code looks for IO.sys; in the case of OS/2, the Bootsect.dos code looks for Os2ldr.exe.
Configuring for Windows NT and MS-DOS
You can dual-boot between Windows NT and MS-DOS on an x86-based computer.
Configuring your computer is easier if you install MS-DOS before you install Windows NT. If you decide to install MS-DOS after you have installed Windows NT, MS-DOS overwrites the Windows NT information in the Partition Boot Sector with its own information. You should have a current Emergency Repair Disk for the computer on which you are installing MS-DOS.
If you have already installed Windows NT and want to install MS-DOS, use one of the following procedures. After you install MS-DOS, you will need to replace the MS-DOS Partition Boot Sector with the Windows NT Partition Boot Sector.
To Install MS-DOS from floppy disks
To Install MS-DOS from the network
After you install MS-DOS, you need to replace the MS-DOS Partition Boot Sector with the Windows NT one. To be able to dual-boot MS-DOS, you also need to create the file Bootsect.dos. The next procedure does both of these things.
To Restore the Windows NT Partition Boot Sector
When you restart the computer, you can select a Windows NT installation or MS-DOS from boot loader screen.
After you have installed MS-DOS and replaced the Partition Boot Sector, it is a good idea to make a MS-DOS bootable floppy disk. This floppy disk should include the MS-DOS files, as well as the Master Boot Record and Partition Boot Sector for each boot partition. See "MS-DOS Bootable Floppy Disk" in Chapter 20, "Preparing for and Performing Recovery," for information about creating this disk.
Configuring for Windows NT and Windows 95
You can configure your computer to start either of these two operating systems. Currently, your installations are easier and less error-prone if you install Windows 95 first and then install Windows NT. This order is recommended because sometimes Windows 95 replaces a Windows NT Partition Boot Sector with its own Partition Boot Sector. A Windows 95 Partition Boot Sector causes a problem for NTFS volumes, because the Windows 95 Partition Boot Sector is for a FAT partition. Windows NT can no longer access the NTFS volume. If you install Windows 95 first, use the installation procedures provided with the Windows 95 CD-ROM.
If you want to be able to triple-boot Windows 95, Windows NT, and MS-DOS, you should install MS-DOS first, as described in "Triple-booting Windows NT, Windows 95, and MS-DOS," presented later in this chapter.
If you have Windows NT installed, and want to be able to install and dual-boot Windows 95, you must configure Windows NT to dual-boot with MS-DOS. See "Configuring for Windows NT and MS-DOS," presented earlier in this chapter, for the procedures to install MS-DOS if you do not already have it installed. Then use the procedures described in "Triple-booting Windows NT, Windows 95, and MS-DOS," presented later in this chapter.
Configuring for Windows NT, Windows 95, and MS-DOS
On an x86-based computer, you can configure your computer to triple-boot one of these three operating systems. You should install them in the following order:
Install each of these operating systems using their standard installation procedure. To start Windows NT, select the instance to start on the boot loader screen. You can also select Windows 95 from the boot loader screen.
To start MS-DOS, first select Windows 95 from the boot loader screen. Select ENTER on the screen, and press either the F4 or the F8 key. When you press F8, Windows 95 displays its Startup menu. Select Previous version of MS-DOS to start MS-DOS. Using the F4 key bypasses the Windows 95 Startup menu and starts MS-DOS directly.
Another way to be able to start all three of these operating systems is to configure your computer for a dual-boot of Windows NT and Windows 95, and start MS-DOS from an MS-DOS bootable floppy disk.
If you install Windows 95 in an existing Windows folder rather than doing a clean install, you need to edit Msdos.sys to enable Windows 95 to dual-boot MS-DOS. Do this by making the file visible, and then turning off the read only attribute. You can then change the file.
To Enable startup of MS-DOS from Windows 95
If you upgrade or reinstall Windows 95, Setup deletes any of these files that it finds in your MS-DOS folder and replaces them with the Windows 95 versions in the Windows95 folder and Windows95\Command folder:
If you already have a dual-boot configuration of Windows NT and MS-DOS, you can install Windows 95 by using the following procedure. You should have a current Emergency Repair Disk for your Windows NT installation(s).
To Install Windows 95 on a Windows NT/MS-DOS dual-boot configuration
After you successfully install Windows 95 and restart the computer, the Windows NT boot loader screen should appear and you can choose between Windows NT and Windows 95. Windows 95 is the first entry on the screen. If you want to make Windows NT the default, see "Contents and Purpose of Boot.ini," presented later in this chapter, for information about changing the order of the selections.
If the Windows NT boot loader screen does not appear, restore the Windows NT Partition Boot Sector by using the procedure in "Dual-booting Windows NT and MS-DOS," presented earlier in this chapter.
Note If you do not install Windows 95 on the C drive, Windows 95 Setup creates a hidden, read only folder on your C drive that has the same name as the folder into which you are installing Windows 95.
Configuring for a Multi-boot With OS/2
If you want to install OS/2, this is the order in which you should install the operating systems:
This is the safest order in which to install all four operating systems. MS-DOS, Windows 95, and Windows NT all have to share a system partition (C:), but can be installed on their own individual partition. They can also be installed in the same partition, but Windows 95 and Windows NT must be installed in different folders. OS/2 requires its own primary partition on the first hard disk, and also requires a second, small primary partition for the BOOTLOADER.
If done correctly, the startup sequence will be:
The above sequence work if you install fewer than the four operating systems.
Dual-booting on RISC-based Computers
On RISC-based computers, you can install and dual-boot multiple versions of Windows NT, and you can also install and startup Unix. The Setup program for the operating system being installed updates the NVRAM with information for starting the operating system. The last operating system installed sets the NVRAM to have itself as the default operating system to start. See the section "Manage Boot Selection Menu," presented later in this chapter for information on changing the default operating system.
Control Sets in the Registry
A control set contains system configuration information, such as which device drivers and services to load and start. Control sets are stored in the Registry as subkeys of HKEY_LOCAL_MACHINE \SYSTEM. There can be several control sets, depending on how often you change system settings or have problems with the settings you choose. A typical installation of Windows NT contains these control set subkeys:
The CurrentControlSet subkey is a pointer to one of the ControlSet00x keys. The Clone control set is a clone of the control set used to initialize the computer (either Default or LastKnownGood), and is created by the Kernel initialization process each time you start your computer. The Clone control set is not available after a user logs on.
In order to better understand how these control sets are used, you should know about the Registry subkey HKEY_LOCAL_MACHINE \SYSTEM \Select, which contains the following values:
Each of these values contain a REG_DWORD data type, which refers to a specific control set. For example, if the Current value is set to 0x1, then CurrentControlSet is pointing to ControlSet001. Similarly, if LastKnownGood is set to 0x2, then the Last Known Good control set is ControlSet002. The Default value is usually the same value as Current. Failed is the control set that was pointed to by Default when a user last started the computer by using the LastKnownGood control set.
The section titled "Selecting the Configuration to Use," presented earlier in this chapter, describes initializing Windows NT by using either the Default configuration or the LastKnownGood configuration. When you select the Default configuration, the Kernel uses the value of Default to determine which control set to use.
There are only two times when the Kernel attempts to load the LastKnownGood configuration:
Starting by using the LastKnownGood control set provides a way to recover from problems such as:
The LastKnownGood option is useful only in cases of incorrect configurations. It does not solve problems caused by corrupted or missing device drivers or files.
Important If you select the Last Known Good Configuration, any configuration changes made during the last system boot are lost.
Once you have logged on, the CurrentControlSet is that one that is changed whenever you make changes to your configuration by using options in Control Panel. If you are manually editing a control set for some reason, the CurrentControlSet is the only one that you should change.
If you are not sure where to look under the CurrentControlSet for a particular key, you can use Find Key on the View menu of the Windows NT Registry Editor. Each control set contains two subkeys: Control and Services. Control contains miscellaneous system information, such as the size and location of the page file. Services contains device driver information, such as file system drivers, Kernel drivers, and status information for each.
Note There are two Registry Editor programs on the Windows NT Workstation product CD, Regedt32.exe and Regedit.exe. You can use either one to view the Registry.
There is a Start value for each Services subkey in the Registry key HKEY_LOCAL_MACHINE \SYSTEM<control set>\Services\DriverName. It specifies the starting values for the device or service, as follows:
These are the possible ErrorControl values in the Registry key HKEY_LOCAL_MACHINE \SYSTEM<control set>\Services\DriverName:
Contents and Purpose of Boot.ini (x86-based Computers)
When you install Windows NT on an x86-based computer, Windows NT Setup puts the Boot.ini file at the root of the system partition. NTLDR uses information in the Boot.ini file to display the screen from which you select the operating system to start.
Here is a sample Boot.ini file:
[boot loader] timeout=30 default=multi(0)disk(0)rdisk(0)partition(1)\WINNT [operating systems] multi(0)disk(0)rdisk(0)partition(1)\WINNT="Windows NT Workstation Version 4.0" multi(0)disk(0)rdisk(0)partition(1)\WINNT="Windows NT Workstation Version 4.0 [VGA mode]" /basevideo /sos C:\="Windows 95"
The Boot.ini file has two sections, [boot loader] and [operating system], which are described in the next two sections.
[boot loader] Section
This section contains the following information:
[operating systems] Section
This section contains the list of available operating systems. Each entry includes the path to the boot partition for the operating system, the string to display in the boot loader screen, and optional parameters. There is an example of the use of this section of the Boot.ini file in the section titled "Boot Loader Screen (x86-based Computers)," presented earlier in this chapter.
The Boot.ini file supports starting of multiple versions of Windows NT operating systems, as well as starting one other operating system. The other operating systems that can be included in the Boot.ini file are Windows 95, MS-DOS, and OS/2. The section "Configuring the Computer for Dual-booting and Triple-booting," presented earlier in this chapter, contains more information about the other operating systems.
There are several switches that you can add to the end of the Windows NT entries in the [operating system] section of the Boot.ini file. They are not case sensitive. Chapter 21, "Troubleshooting Startup and Disk Problems," contains more information about many of these switches. For information about the debugger, see Chapter 39, "Windows NT Debugger."
When you install Windows NT, the Boot.ini file has the Read Only, System, and Hidden attributes set. You can edit the timeout and default parameters in the Boot.ini file by using the System option on Control Panel, regardless of the value of these attributes.
If you want to edit the Boot.ini file by using a text editor, you need to make the file visible before you can open it, and you need to turn off Read Only to be able to make changes to it. You can change the attributes by using My Computer, Windows NT Explorer, or the command prompt.
To change the attributes in My Computer or Windows NT Explorer
To change the attributes by using command prompt, enter:
attrib -s -h -r boot.ini
If you change the path to the Windows NT boot partition, make sure to edit both the default path and operating system path entries. If you change one but not the other, a new choice is added to the boot loader screen, with the default designator next to it.
Using a RISC-based Computer's Boot Menu
This section describes using the firmware menus on a RISC-based computer to change environment information in the NVRAM. There are three types of RISC-based computers: Alpha, MIPS, and PowerPC. The examples in this section are for an Alpha AXP-based computer, running firmware version 3.5-11. Menus for other versions of the firmware might be different. Menus and processing on MIPS-based computers and PPC-based computers are similar.
When you start an Alpha-based computer, you see the Boot menu, which looks like this:
ARC Multiboot Alpha AXP Version 3.5-11 Copyright (c) 1993 Microsoft Corporation Copyright (c) 1993 Digital Equipment Corporation Boot Menu: Boot Windows NT Workstation Version 4.0 Boot an alternate operating system Run a program Supplementary menu. . . Use the arrow keys to select, then press Enter.
The first two selections are described in the section titled "Boot Menu (RISC-based Computers)," presented earlier in this chapter. Information about those selections is not repeated here.
For more information about ARC path names, which are used in boot selections, see Chapter 20, "Preparing for and Performing Recovery."
Selecting Run a Program
When you select Run a program, you see the following screen:
ARC Multiboot Alpha AXP Version 3.5-11 Copyright (c) 1993 Microsoft Corporation Copyright (c) 1993 Digital Equipment Corporation Program to run:
From this prompt, you can start any program that has been compiled for an Alpha-based computer. You must know the complete ARC path to the program, unless the NVRAM has the correct environment variables defined for devices. For example, if there are environment variables for the cd-rom drive (CD:) or the floppy disk (A:), you can use them instead.
For example, to start Windows NT Setup, where the CD is a default device on the computer, you can type the following:
Program to run: CD:\alpha\setupldr
When running a program stored on the hard disk, you must use the full ARC pathname and filename, such as the following:
Program to run: scsi(0)disk(0)rdisk()partition(1)\alpha\setupldr
If you try to use the MS-DOS syntax to run a program on the hard disk, you get an error message like the following:
Program to run: C:\alpha\setupldr Pathname is not defined Press any key to continue...
Note The firmware routines can access only FAT partitions or CD-ROM drives. They cannot access NTFS partitions.
Arcinst.exe is an AXP native mode application program (requires no operating system) that performs the same functions as the MS-DOS-based utilities Fdisk and Format. You can use Arcinst to define and automatically format partitions. This application program is on the Windows NT product CD.
To start Arcinst, type in the following at the Program to run prompt:
Program to run: cd:\alpha\arcinst
When the program starts, it displays the following menu:
Arc Installation Program Version 4.00 Copyright (c) 1995 Microsoft Corporation Configure Partitions Exit
If you select Configure Partitions, you see the following menu:
Arc Installation Program Version 4.00 Copyright (c) 1995 Microsoft Corporation Create Partition Delete Partition Make Existing Partition into System Partition Exit
Arcinst creates the first two partitions on a hard disk as physical partitions. The second partition is always an extended partition; any additional partitions are defined as logical drives within the extended partition. There are no user-defineable parameters for these options. Drive letters are not assigned, since the ARC specification for path names does not include them.
After creating any partition, the system automatically formats it as FAT. There is no option to skip formatting the new partition. This is a sample of the information you see when you select Create Partition:
Arc Installation Program Version 4.00 Copyright (c) 1995 Microsoft Corporation Scsi bus 0, Identifier 3, Disk 0 (scsi(0)disk(3)rdisk(0)) Scsi bus 0, Identifier 0, Disk 0 (scsi(0)disk(0)rdisk(0))
When you select one of the disks, you see the following screen:
Enter size in MB (1-191):
The available size is the unpartitioned disk space remaining on the disk. When you enter the size, you see messages such as the following:
Partition successfully created. Press any key to continue.... Formatting scsi(0)disk(0)rdisk(0)partition(3) 99 percent formatted
When formatting completes, you automatically return to the Configure Partitions menu.
If the disk that you select has no unpartitioned area, you see the following message:
Disk is full Press any key to continue...
You can delete any partition or logical drive, in any order. When you delete a volume, any data on that volume is no longer accessible. When you select Delete Partition, you see information such as this:
Arc Installation Program Version 4.00 Copyright (c) 1995 Microsoft Corporation Scsi bus 0, Identifier 3, Disk 0 (scsi(0)disk(3)rdisk(0)) Scsi bus 0, Identifier 0, Disk 0 (scsi(0)disk(0)rdisk(0))
When you select one of the disks, you see a screen similar to this one:
1010 MB Fat Partition
Select a volume to delete. If the partition is the system partition, you get an error message like:
The selected partition is (or contains) a system partition Are you sure you want to delete it (y/n)?
If the partition is not the system partition, you see a screen similar to:
509 MB Extended Partition also results in the deletion of: 509 MB HPFS/NTFS Logical Volume Are you sure you want to delete it (y/n)?
When you enter y to either of these preceding questions, you see the following screen:
Partition deleted successfully. Press any key to continue.
When you press a key, you return to the Configure Partitions menu.
Make Existing Partition into System Partition
When you select this option, you see a screen similar to the following:
Arc Installation Program Version 4.00 Copyright (c) 1995 Microsoft Corporation Scsi bus 0, Identifier 3, Disk 0 (scsi(0)disk(3)rdisk(0)) Scsi bus 0, Identifier 0, Disk 0 (scsi(0)disk(0)rdisk(0))
If the partition you select is already the system partition, you see the following screen:
Partition is already a system partition. Press any key to continue...
Otherwise, you see information like the following:
Partition 2 (200 MB HPFS/NTFS)
The system partition must be formatted as FAT. Selecting an NTFS partition results in this message:
System partitions must be formatted with the FAT filesystem. Do you wish to format the chosen partition (y/n)?
When you enter y, this message is displayed:
All existing data will be lost. Are you sure (y/n)?
Entering y causes the partition to be formatted as FAT.
99% complete Partition added successfully. Press any key to continue...
You automatically return to the Configure Partitions menu.
Running the Repair Procedure
If your system files or Partition Boot Sector are corrupt, and you are unable to restart by using the Last Known Good Configuration, you can use the Repair process in Windows NT Setup to repair your system.
To repair a Windows NT installation, you need the configuration information on \%systemroot%\Repair or the Emergency Repair Disk that you created when you installed Windows NT (or you created later by using the Repair Disk utility).
To start the Windows NT Setup program from the CD-ROM, select Run a program from the Boot menu and enter the following at the prompt:
Program to run: CD:\alpha\setupldr
Once setupldr starts, the procedures are the same as for an x86-based computer.
Selecting Supplementary Menu
When you select the Supplementary menu option from the Boot menu, the firmware displays this screen:
ARC Multiboot Alpha AXP Version 3.5-11 Copyright (c) 1993 Microsoft Corporation Copyright (c) Digital Equipment Corporation Supplementary menu: Install new firmware Install Windows NT from CD-ROM Set up the system... Display hardware configuration Boot menu... Use the arrow keys to select, then press Enter.
Install New Firmware
Installing new firmware results in the following:
If you want to save the information that is currently in the NVRAM, you can use the saveenv and restenv utilities, which are available from Digital Equipment Corporation. Run these utilities from the Run a program menu to save your current NVRAM settings to a file on the disk, and then restore them.
To upgrade the firmware without wiping out all settings.
Install Windows NT from CD-ROM
When you select Install Windows NT from CD-ROM, the firmware displays the message:
Loading Microsoft Windows NT Setup. . .
The next screen is the standard Windows NT Setup screen. The rest of the installation is identical to installing Windows NT on an X86-based computer.
You can also run the Repair procedure by selecting this option. When Windows NT Setup displays the Welcome to Setup screen, select R for repair. The rest of the repair procedure is identical to what happens on an x86-based computer.
Set Up the System (Setup Menu)
Selecting Set up the system takes you to the Setup menu, which enables you to change the configuration options for all operating systems, and the computer configurations options stored in the NVRAM. You can change the following types of information:
The following example shows the Setup menu. If you make changes to the computer configuration by making selections from the Setup menu, the additional selection:
Supplementary Menu, and save changes...
appears as the last line of the menu. Changes are not actually saved to the NVRAM until you make this selection. This example includes the additional line.
ARC Multiboot Alpha AXP Version 3.5-11 Tuesday, 2-20-96 2:53:19 PM Copyright (c) 1993 Microsoft Corporation Copyright (c) 1993 Digital Equipment Corporation Setup menu: Set system time Set default environment variables Set default configuration Manage boot selection menu... Setup autoboot Machine specific setup... Edit environment variables Reset system to factory defaults Help Supplementary menu, and do not save changes... Supplementary menu, and save changes... Use the arrow keys to select, then press Enter.
If any of the changes that you make by using the Setup menu result in inconsistent information in the NVRAM, the selection with the error is in yellow text. And the following message is displayed at the bottom of the screen, also in yellow text:
The yellow items should be done before booting Windows NT
Note The Setup menu on other versions of the Alpha-based computer firmware might have different entries. For example, you might have the entry Run EISA configuration utility from floppy.
Set System Time
To set the system date and time, select Set system time from the Setup menu. You can enter the following information:
Tuesday, 2-20-1996 3:03:48 PM Enter the new date (mm-dd-yy) : Enter time (hh:mm:ss) :
When setting the time, you must enter the time in 24-hour format. For example, the time listed above should be entered as 15:03:48.
You automatically return to the Setup menu when you enter both fields.
Set Default Environment Variables
To set the defaults for booting, select Set default environment variables on the Setup menu. This example shows the user selecting the SCSI Hard Disk as the location of the default system partition.
Tuesday, 2-20-1996 3:08:48 PM Enter location of default system partition: Select media: SCSI Hard Disk Floppy Disk CD-ROM Enter SCSI bus number: 0 Enter SCSI ID: 0 Enter partition (must be FAT or NTFS): 1
Set Default Configuration
To set the default configuration, select Set default configuration on the Setup menu. The available selections depend upon your computer hardware.
Tuesday, 2-20-1996 3:09:28 PM Select monitor resolution: 1280x1024 1024x768 800x600 640x480 Select floppy drive capacity: 5.25" 1.2MB 3.5" 1.44MB 3.5" 2.88MB Is there a second floppy: Yes No Select keyboard: U.S. 101-key keyboard Japanese 106-key keyboard French 102-key keyboard German 102-key keyboard Spanish 102-key keyboard Spanish variation Canadian French 102-key keyboard Swiss 102-key keyboard Italian 102-key keyboard Finnish/Swedish keyboard Norwegian keyboard Danish 102-key keyboard Enter SCSI Host ID (0-7) for SCSI bus number :
After selecting the setting in each group, you are returned to the Setup menu.
Manage Boot Selection Menu
When you select Manage boot selections menu on the Setup menu, you can configure and manage the operating systems that appear on the Boot menu at startup. You can also configure custom startup folders and files if you have installed multiple copies of Windows NT.
The following choices are available on the Boot selections menu:
Tuesday, 2-20-96 2:59:19 PM ARC Multiboot Alpha AXP Version 3.5-11 Copyright (c) 1993 Microsoft Corporation Copyright (c) 1993 Digital Equipment Corporation Boot selections menu: Add a boot selection Change a boot selection Check boot selections Delete a boot selection Dump boot selections Rearrange boot selections Setup menu... Use the arrow keys to select, then press Enter.
Add a Boot Selection
Select Add a boot selection on the Boot selections menu if:
When you make this selection, you can enter information similar to the following:
Note The right justified arrows (<----) in these examples indicate which selection was made, or the information that was entered.
Tuesday, 2-20-96 3:09:19 PM Select a system partition for this boot selection: SCSI Bus 0 Hard Disk 0 Partition 1 New system partition Enter location of system partition for this boot selection: Select Media: SCSI Hard Disk <--------------------------------------------------- Floppy Disk CD-ROM Enter SCSI bus number: 0 <--------------------- Enter SCSI ID: 2 <--------------------- Enter Partition (must be FAT or NTFS): 1 <--------------------- Enter the osloader folder and name: \os\winnt40\osloader.exe <--------- Is the operating system in the same partition as the osloader: Yes No <---------------------------------------------------------------- Enter the location of os partition: Select Media: SCSI Hard Disk <--------------------------------------------------- Floppy Disk CD-ROM Enter SCSI bus number: 0 <------------------------------------- Enter SCSI ID: 2 <------------------------------------- Enter Partition: 2 <------------------------------------- Enter the operating system root folder: \winnt <-------------- Enter a name for this boot selection: Boot Shadow Disk <-------------- Do want to initialize the debugger at boot time: Yes No <----------------------------------------------------
Change a Boot Selection
When you select Change a boot selection on the Boot selections menu, you can change environment variables for any of the boot selections that you have defined. This is a sample screen:
Tuesday, 2-20-96 3:15:09 PM Selection to edit: Boot Windows NT Workstation 4.0 (Default) Boot Windows NT Workstation 3.51
When you select one of the entries, you see a screen like this one:
Tuesday, 2-20-96 3:17:19 PM Use arrow keys to select a variable, ESC to exit: Name: Environment variables for boot selection 1: LOADIDENTIFIER= Boot Windows NT Workstation 4.0 SYSTEMPARTITION=scsi(0)disk(0)rdisk()partition(1) OSLOADER=scsi(0)disk(0)rdisk()partition(1)\os\winnt40\osloader.exe OSLOADPARTITION=scsi(0)disk(0)rdisk()partition(1) OSLOADFILENAME=\winnt OSLOADOPTIONS=nodebug
Use the arrow keys to select the environment variable to edit and press ENTER. The screen changes to have the heading Value: under Name:. For instance, if you select OSLOADOPTIONS and press ENTER, you see the following:
Name: OSLOADOPTIONS Value: nodebug
Edit the value, and press ENTER when done. Press the ESCAPE key to exit this menu and return to the Boot selections menu.
Check Boot Selections
Under normal circumstances, when you select Check boot selections on the Boot selections menu, the screen briefly displays the various startup selections as they are checked for validity. If there is a problem, such as an invalid path or file, the following information is displayed:
Tuesday, 2-20-96 3:25:11 PM Problems were found with Windows NT Workstation 4.0... Choose an action: Ignore problems with this boot selection Delete this boot selection Change this boot selection
The error is displayed in yellow text below the options, such as the following:
OSLOADER cannot be found, value is: scsi(0)disk(0)rdisk(0)partition(1)\os\nt\xsloader.exe
The firmware only checks that the paths are valid and that the files or folders exist. It does not check file sizes, version numbers, dates, switches, or any other fields that might indicate consistency problems.
The firmware automatically returns you to the Boot selections menu.
Delete a Boot Selection
If you have deleted a Windows NT installation from your computer, you should select Delete a boot selection on the Boot selections menu to remove it from the NVRAM. This is the screen you see when you select this option:
Tuesday, 2-20-96 3:25:09 PM Selection to delete: Boot Windows NT Workstation 4.0 (Default) Boot Windows NT Workstation 3.51
Use the arrow keys to highlight the selection you want to delete, and press ENTER. There are no warnings or checks, and the selection is immediately deleted. Changes are not saved to NVRAM until you exit the Setup menu, however.
Dump Boot Selections
When you select Dump boot selections on the Boot selections menu, the NVRAM resets to no boot selections.
This is a sample screen:
LOADIDENTIFIER= Boot Windows NT Workstation 4.0;Boot Windows NT Workstation 3.51 SYSTEMPARTITION=scsi(0)disk(0)rdisk(0)partition(1); scsi(0)disk(0)rdisk(0)partition(2); OSLOADER=scsi(0)disk(0)rdisk(0)partition(1)\os\winnt40\osloader.exe; scsi(0)disk(0)rdisk(0)partition(2)\os\winnt351\osloader.exe; OSLOADPARTITION=scsi(0)disk(0)rdisk(0)partition(1); scsi(0)disk(0)rdisk(0)partition(2); OSLOADFILENAME=\winnt;\winnt OSLOADOPTIONS=nodebug;sos debug baudrate:19200 Press any key to continue...
Changes are not saved until you exit the Setup menu, and select Supplementary Menu, and save changes. If you save changes when exiting, the only ways to restore boot selections are to manually reenter the information or use the Emergency Repair disk.
Rearrange Boot Selections
The most common reason for rearranging the boot selections is because you have added a boot selection, which is automatically placed at the top of the list.
You see a screen like this one when you select Rearrange boot selections on the Boot selections menu:
Tuesday, 2-20-96 4:01:03 PM Pick selection to move to the top, ESC to exit: Boot Windows NT Workstation 4.0 (Default) Boot Windows NT Workstation 3.51
Use the arrow keys to highlight the selection you want to move to the top of the list, then press ENTER. You can do this repeatedly to rearrange the boot selection into any order you want.
As before, changes are not saved until you exit the Setup menu, and select Supplementary Menu, and save changes.
When you are finished with all of your changes on the Boot Selections menu, you can select Setup menu to return to the Setup menu.
The Setup autoboot selection on the Setup menu enables you to set your computer to automatically start the default selection if you do not make a selection from the Boot Loader menu.
You see a screen like this one when you select this option on the Setup menu:
Wednesday 2-21-1996 8:01:36 AM Should the system autoboot: Yes No Enter Countdown value (in seconds): 30
The Enter Countdown value prompt appears only if you select Yes. The countdown value provides the same functionality as the timeout value in the Boot.ini file on an x86-based computer.
Machine Specific Setup
When you select Machine specific setup on the Setup menu, you can set environment variables that are specific to the computer, such as:
Wednesday 2-21-1996 11:01:36 AM PCI Parity checking currently set to: Off Set PCI Parity checking currently set to: On Setup menu ...
Selecting one of the options sets the environment variable to the value specified. Selecting Setup menu returns you to that menu.
Edit Environment Variables
You can add, delete, or change information for the environment variables by selecting Edit environment variables on the Setup menu. The screen displays the variables that are defined, and their values, such as this example:
Wednesday 2-21-1996 8:09:16 AM Use the arrow keys to select a variable, ESC to exit: Name: Environment variables: CONSOLEIN=multi()key()keyboard()console() CONSOLEOUT=multi()video()monitor()console() FWSEARCHPATH=scsi(0)disk(0)rdisk()partition(1) A:=multi(0)disk(0)fdisk(0) FLOPPY=2 FLOPPY2=N KEYBOARDTYPE=0 TIMEZONE=PST8PDT
You can add environment variables by typing in the name of the new variable at the Name: prompt and pressing ENTER. A prompt for Value: appears beneath the Name: prompt, and you enter the value.
For instance, to add the countdown variable:
Name:COUNTDOWN Value: 20
To delete an environment variable, select it with the arrow keys, or type in the name at the Name: prompt. Then press ENTER at the Value: prompt. Environment variables with no string value are deleted from the NVRAM.
Reset System To Factory Defaults
Be careful when you select this option. When you execute this command, you might no longer be able to start the computer. Some reasons for the failure are:
Before you execute the command, write down all configuration information that you need to know, such as:
This is a sample screen:
Wednesday 2-21-1996 8:15:16 AM This command will overwrite the environment, configuration, and boot selections with new information. Are you sure you want to do this? Yes No
Selecting Yes causes the default configuration information to be saved to NVRAM. Once you do this, there is no way to recover any previous configuration information. You have to rebuild all custom options and configuration parameters by using the firmware menus.
This selection displays the system help screen.
Wednesday 2-21-1996 8:26:11 AM Do the following steps, in this order, to set up the system: 1. Set system time. 2. Set default environment variables. 3. Set default configuration. 4. Create at least one boot selection. 5. Setup autoboot. -> A menu item with an arrow represents a section of the NVRAM with a problem. Select these items (in top to bottom order) to repair the NVRAM before attempting to boot or install Windows NT. "Reset system to factory defaults" does steps 2--5 for a typical system. Home, End, Delete, and Backspace will help you edit strings. The ESCape key returns from a menu and aborts a sequence. The firmware automatically reboots if the configuration is changed. Press any key to continue...
You return to the Setup menu when you press any key.
Exiting the Setup Menu
If you have made changes to the NVRAM by using the Setup menu, there are two ways to exit to the Supplementary menu:
Supplementary menu, and do not save changes... Supplementary menu, and save changes...
If you choose to save the changes, they are saved to NVRAM. If you did not make any changes, the second option does not appear on the screen.
Display Hardware Configuration
Selecting Display hardware configuration on the Supplementary menu displays information about:
This is an example:
Friday 2-23-1996 10:46:15 AM Devices detected and supported by the firmware: multi(0)video(0)monitor(0) multi(0)key(0)keyboard(0) multi(0)disk(0)fdisk(0) multi(0)serial(0) multi(0)serial(1) scsi(0)disk(0)rdisk(0) scsi(0)cdrom(4)fdisk(0) Press any key to continue...
Selecting any key displays a list of supported hardware, such as the following:
Friday 2-23-1996 10:46:55 AM Alpha AXP Processor and System Information: Processor ID 21066 Processor Revision 2 System Revision 1 Processor Speed 166.66Mhz Physical Memory 32 MB Backup Cache Size 256 KB Press any key to continue...
When you press any key, the firmware displays the next set of information. When all hardware information has been displayed, selecting any key returns you to the Supplementary menu.
When you select Boot menu on the Supplementary menu, the firmware returns you to the Boot menu.