Multibooting in Windows XP Made Easy
Published: September 10, 2001
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You may be compelled to run more than one operating system on a single computer for a variety of reasons—to replicate customer environments, to run specialized applications, or to test new operating systems before committing completely to them. I run several operating systems so that I can test and write about them, as well as help support them.
Over the years, I've run as many as five or six different operating systems on the same computer, although these days I run only three or four, depending on whether you count Windows XP Professional and Windows Advanced Server as different operating systems. Because the price of hard drive space is cheap today, it's remarkably easy to run multiple operating systems on the same computer without spending a fortune.
File System Considerations
If you need to run more than one operating system on your computer, first you must understand what file system types are supported by which operating systems. A file system is the method for naming, storing, and organizing files on your computer. Just about everyone supports plain old FAT16, but enabling support for FAT32 and NTFS requires some advance planning. If your mix of operating systems includes UNIX or Linux, their file systems won't be visible to the versions of the Windows operating system you've installed.
The easy solution would be to use FAT16 for all your Windows versions, but this solution has its own problems. FAT16 partitions don't work well for today's larger hard drives. The FAT16 file system is limited to 2-GB partitions. Many features of Windows NT, Windows 2000, and Windows XP are supported only by using NTFS, such as better compression for storage, and support for larger partitions and files sizes. My preference is to use FAT32 for Windows 98 and Windows Me, and to use NTFS for Windows NT, Windows 2000, and Windows XP. Remember that versions of Windows NT earlier than Windows NT 4, Service Pack 4 do not support the version of NTFS used by Windows 2000 and Windows XP, and even Windows NT 4, Service Pack 4 does not support all the features of NTFS. Also, Windows NT doesn't support FAT32.
To provide the greatest flexibility, put your general purpose applications on a partition that is formatted with a file system type supported by all the operating systems that need to access the applications. My preference is to use FAT16 for this, although as soon as I stop having to support Windows NT 4, this will change to FAT32.
Partitions, Volumes, Drives, and Disks
The first rule of partitions is that every operating system needs one. Actually, every OS needs its own drive letter (technically, a logical drive), but it can share an extended partition with other operating systems as long as they're each in their own logical drive. If your mix of operating systems includes UNIX and/or Linux, they will require their own primary partition, separate from any Windows operating system you have installed.
So plan how to divide the available hard disk space by the number of operating systems you want to install and by how much space you'll allot to each OS. Plus room for applications, of course. If you plan to boot three operating systems on one computer, and install applications in one place where all the operating systems can use them, you'll need four partitions or logical drives of sufficient size—these days, I figure not less than 2 GB per operating system. But don't actually install anything yet—we need to do a little planning before we install the operating systems, because the order of installation is critical to our success.
Correct Installation Order is Essential
The order of installation is critical if you want a successful multiboot installation. In general terms, install non–Microsoft operating systems and earlier versions of the Windows operating system first. This would mean installing UNIX or Linux operating systems first; then Windows 95 or Windows 98 or Windows Me; then Windows NT; and finally, Windows 2000 and/or Windows XP. (In the unlikely event that you're installing MS–DOS, you can install that either before or after UNIX– or Linux–based operating systems, and generally I'd opt for before.) It's also important to understand that, without using a third–party product to help out, you can't install non-Microsoft operating systems, or Windows 95 and Windows 98 on the same computer, and that you can install only a single version of Windows95/98/Me. But you can install as many different versions of Windows NT and later versions of the Windows operating system as you have available logical drives, with the sole caveat that you must install all Windows NT versions before you install any Windows 2000 or Windows XP versions.
Let's take a typical installation. Our target computer must be able to boot into Windows 98, Windows NT 4 Workstation, Windows 2000 Professional, and Windows XP Professional. We have a 2–GB partition to hold our programs and the whole thing must fit on a single 10–GB hard drive. No problem. First, we partition the hard drive into two partitions: a 2–GB primary partition, and an 8-GB extended partition using FDisk. In the extended partition, we'll create four logical volumes—D, E, F and G—to hold our remaining operating systems and our programs.
After the disk is partitioned, format the primary partition using the FAT16 file system and install Windows 98 on it. So far so good. Now, format your D drive with FAT16 as well. Eventually, you'll install your programs on D drive.
Next, install Windows NT 4 Workstation. You will install this on any of the logical volumes not already used (either E drive, F drive or G drive) and choose NTFS as your file system. Leave D drive alone, because your applications go there where they're visible to all operating systems. When you install Windows NT, it recognizes that you already have Windows 98 on the computer. Then it automatically sets up for dual booting between Windows 98 and Windows NT by creating a boot.ini file, which creates a menu of available operating systems. After you have Windows NT 4 installed, immediately apply Service Pack 6, before you install Windows 2000.
Finally, install Windows 2000 and Windows XP, each in its own logical volume. Again, choose NTFS as the file system. As you install them, they are automatically added to the boot.ini file on your C drive, which lets you choose operating systems at start up.
Third Party Tools
If you want to run Windows 98 and Windows Me on the same computer, or you need to run a non–Microsoft operating system, you need a third party tool such as Boot Magic (included with Partition Magic and some distributions of Linux) or System Commander to make it all work, because this is more than the Windows NT boot manager can handle. Some versions of UNIX (Caldera OpenServer for one) and some distributions of Linux include their own boot manager program that can help, or go with System Commander or Boot Magic.
