This chapter presents approaches to solving common problems encountered when installing or configuring a computer running Internet Information Server (IIS) or Peer Web Services. This chapter provides information about:

• Troubleshooting Internet Information Server—specific troubleshooting techniques or problems.

• Sources of troubleshooting information—places to go for more troubleshooting information or general information about Windows NT.

• Using troubleshooting tools—Windows NT Server tools that can be useful when determining a problem with Internet Information Server.

Troubleshooting Internet Information Server

This section provides four types of troubleshooting information:

• A procedure to test Internet Information Server operation.

• Where to go for more information when you receive Windows NT error messages.

• The meaning of Hypertext Markup Language (HTML) 1.0 status codes and messages presented to users.

• Tips for troubleshooting specific problems, listed by category of problem.

Testing an Installation

The default installation of Internet Information Server contains sample files that you can use to test the functionality of your Internet Information Server World Wide Web (WWW) service.

To test the WWW service on your server

1. Ensure your computer has an active connection to your intranet and that name resolution is working properly.

2. Start Microsoft Internet Service Manager and use it to verify that the WWW service is running.

3. In Internet Explorer, click Open on the File menu and type the Uniform Resource Locator (URL) for the home directory of your new server.

   The URL is http:// followed by the NetBIOS name of your server. For example, if your server is called Myserver you type

   http://myserver

   A sample HTML page appears. If it does not, try the full path to access the samples page, for example

   http://myserver/samples

Windows NT Messages

The Messages database, included in this Resource Kit, is another source of general troubleshooting information. Thousands of Windows NT messages are documented, along with the probable cause of errors that generate them and recommended solution to each. This database includes documentation of the STOP messages that appear with a blue screen when the system fails. For more general information on blue-screen messages, see Chapter 38, "Windows NT Executive STOP Messages," in the Windows NT Workstation Resource Guide.

HTTP 1.0 Status Codes and Reason Phrases

Clients can receive an HTTP status code and matching reason phrase after making a request to the IIS server.

The Hypertext Transport Protocol (HTTP) defines status codes and reason phrases that HTTP servers such as Internet Information Server can return to clients.

Status codes are returned by the server in response to a request. The three-digit code acknowledges an attempt to understand and satisfy the request. The reason phrase gives a short description of the status code.

Note: This section describes the status codes and reason phrases from the HTTP 1.0 Internet-draft. Note that Internet-drafts are valid for a maximum of six months. You should check the full text of the latest draft for the most current information. To learn the current status of any Internet draft, use FTP to check the 1id-abstracts.txt file in the Internet-Drafts directory on ftp.is.co.za (Africa), nic.nordu.net (Europe), munnari.oz.au (Pacific Rim), ds.internic.net (US East Coast), or ftp.isi.edu (US West Coast).

The first digit of the status code defines the class of response. There are five possible values for the first digit of the status code. Table 8.1 lists the five classes of codes and the reasons they are returned by the server.
Table 8.1 HTTP 1.0 Status Code Classification

Code	Class	Use
1xx	Informational	Not used, but reserved for future use.
2xx	Success	The action was successfully received, understood, and accepted.
3xx	Redirection	Further action must be taken in order to complete the request.
4xx	Client Error	The request contains incorrect syntax or cannot be fulfilled.
5xx	Server Error	The server failed to fulfill an apparently valid request.

Table 8.2 presents the individual values of the numeric status codes defined for HTTP 1.0. The reason phrases listed here are those that are recommended by the HTTP 1.0 protocol and are used by Internet Information Server.
Table 8.2 HTTP 1.0 Status Codes, Reason Phrases, and Meanings

Status code	Reason phrase	Meaning
200	OK	The request has succeeded. The information returned with the response is dependent on the method used in the request, as follows: GET An entity1 corresponding to the requested resource is being sent in the response. HEAD The response must contain only the header information and no Entity-Body. POST An entity describing or containing the result of the action is being sent in the response.
301	Moved permanently	The requested resource has been assigned a new permanent URL and any future references to this resource should use that URL.
302	Moved temporarily	The requested resource resides temporarily under a different URL. Because the redirection is sometimes altered, the client should continue to use the Request-URI2 for future requests.
304	Not modified	If the client has performed a conditional GET request and access is allowed, but the document has not been modified since the date and time specified in the If-Modified-Since field, the server responds with this status code and does not send an Entity-Body to the client. Header fields contained in the response should include only information that is relevant to cache managers and that may have changed independently of the date specified in the entity's Last-Modified field. Examples of relevant header fields include Date, Server, and Expires.
400	Bad request	The request could not be understood by the server because of incorrect syntax.
401	Unauthorized	The request requires user authentication.
403	Forbidden	The server understood the request, but refuses to perform the request for an unspecified reason. Authentication will not help and the request should not be repeated.
404	Not found	The server has not found anything matching the Request-URI. The server does not indicate whether the condition is temporary or permanent.
500	Internal server error	The server encountered an unexpected condition that prevented it from fulfilling the request.
501	Not implemented	The server does not support the functionality required to fulfill the request.
502	Bad gateway	The server received an invalid response from the gateway or upstream server it accessed in attempting to fulfill the request.

¹ An entity is a particular representation or rendition of a resource that may be enclosed within a request or response message. An entity consists of metainformation in the form of entity headers, and content in the form of an entity body.

² Uniform Resource Identifier; see the HTTP 1.0 specification for an explanation of URI.

HTTP status codes are extensible, but the codes in Table 8.2 are the only codes that are recognized in current practice and are used by Internet Information Server.

Installation Problems

Cannot Install File During Setup

During Internet Information Server Setup, you can install Open Database Connectivity (ODBC) drivers. If you select ODBC drivers to be installed, the following message can appear when Setup tries to copy ODBC files:

Cannot install file c:\winnt\system32\odbc32.dll. It might be in use.
Close all applications and click Retry.

Click Ignore if you want to skip this file.

This problem occurs when applications that use ODBC drivers are running. However, it also happens when services, such as SQL Executive, are running.

To correct this problem

1. Close all open applications except the Internet Information Server Setup program. (The Error dialog box is displayed.)

2. In Control Panel, double-click Services.

3. Click SQL Executive and then click Stop.

4. Switch back to Internet Information Server Setup (Error dialog box) and click Retry.

Server Configuration Problems

Access Is Denied for Virtual Directories

The Directories property sheet for an Internet Information Server service displays the message "Access is Denied" in the Error column of a virtual directory listing. This message appears after you create a virtual directory in Internet Service Manager by specifying a network share in universal naming convention (UNC) format.

This problem occurs if the user account information is missing or incorrect when the virtual directory is created.

To correct this problem, you must enter the correct user account information by using Internet Service Manager.

To specify a user name for a virtual directory on a network drive

1. In Internet Service Manager, double-click the computer name of the service that uses the virtual directory.

2. Click the Directories property sheet and then select the virtual directory reporting the error.

3. Click Edit Properties. Enter the account information in the following format and then click OK:

   User name: domainname\username

   Password: password

FTP Server Users Experience Delayed Responses

Microsoft Internet Information Server File Transfer Protocol (FTP) clients experience delayed responses to commands when a large number of users are logged on through FTP. This problem occurs sporadically. File transfer speeds are not affected.

The default number of threads per processor (MaxPoolThreads value in Registry) installed on your system is 10. This might be insufficient for a heavily used FTP server because some of the FTP commands use synchronous I/O, causing threads to block while they complete.

To correct this problem

1. Click the Start button, then point to Run. In the Open box, type regedt32.exe and then click OK.

2. Click the HKEY_LOCAL_MACHINE window and locate the following key:

   \System

   \CurrentControlSet
   \Services
   \InetInfo
   \Parameters.

3. From the Edit menu, click Add Value.

4. In the Add Value dialog box, enter the value MaxPoolThreads with the data type REG_DWORD.

5. In the DWORD Editor dialog box, enter a value in the range 0 to 0xFFFFFFFF.

   For example, a twin processor with 500 to 1,000 concurrent users might require 50 or more threads per processor to provide quick response for all FTP client users.

6. Click OK and quit the Registry Editor.

7. Shut down and restart Windows NT.

   Warning: If you use Registry Editor incorrectly it can cause serious, system-wide problems that may require you to reinstall Windows NT to correct them. Microsoft cannot guarantee that any problems resulting from the use of Registry Editor can be solved. Use this tool at your own risk.

Anonymous Users Have Same Access as Domain Users

You allow anonymous users access to specific public Web pages and allow domain users access to additional Web pages. Your server is a primary domain controller that uses the Windows NT File System (NTFS) security permissions. However, after configuration, anonymous users have the same access as domain users.

The problem is that any user account that you create on a primary domain controller automatically becomes a member of the Domain Users group.

In Internet Information Server, you can allow both anonymous and domain users access to the selected Web pages. To do this, select Allow Anonymous and Windows NT Challenge/Response boxes on the WWW property sheet, then use NTFS security permissions to specify access. However, the Internet Information Server anonymous access account, IUSR_computername, becomes a member of Domain Users when Internet Information Server is installed on a primary domain controller. As a result, anonymous users have the same access as the domain users.

To correct this problem, remove IUSR_computername from the global group Domain Users. You must then add the Log On Locally user right to the IUSR_computername account. As an alternative, you can replace the IUSR_computername account on the domain controller with an account that has appropriate permissions.

Cannot Start Internet Information Server Services

When the WWW service cannot automatically start during Windows NT startup, the Event Viewer records the message, "HTTP could not initialize socket library." The options to change properties of Internet Information Server services are unavailable in Internet Service Manager. When you attempt to start the WWW service and FTP service manually, a message states "Data area passed to system call is too small."

To solve this problem, you change the order of protocols listed in the Registry key and move Tcpip to the first entry in the list of values.

HKEY_LOCAL_MACHINE \System

\CurrentControlSet
\Services
\Winsock
\Parameters
\Transports

Clients Cannot See Virtual Directories in Directory Listings

FTP, Gopher, and WWW directory browsing clients (such as Internet Explorer) are not able to see virtual directories.

Internet Information Server does not display virtual directories in directory listings returned to clients.

If you know the name (alias) of the virtual directory, you can work around this limitation by explicitly specifying the name of the virtual directory in the client. In a WWW browser, you include the virtual directory name in the URL, for example:

ftp://myftpserver/ virtual_directory /

In a dedicated FTP client, you explicitly change directories by using the virtual directory name, for example:

cd / virtual_directory

You must type the forward slash (/). Otherwise, cd tries to change the directory from within the client's current directory.

HTTP/1.0 Error 500

The following HTTP server message can be returned for an anonymous user logon request:

HTTP/1.0 500 Server Error (Logon failure: the user has not been granted
the requested logon type at this computer.)

Frequently, this message means that your anonymous user does not have local logon rights.

To make sure an anonymous user can log on locally

1. In the Microsoft Internet Service Manager, open the WWW Service properties sheet. Verify that the anonymous logon user name and password specified here are identical to the user name and password in User Manager.

2. Run User Manager to verify that the Log On Locally user right includes your designated anonymous user name.

   – or –

   Change the anonymous user account to an account that has the Log On Locally user right specified in User Manager.

Client Problems

Netscape Navigator 2.0 Does Not Support Authentication

If you use Netscape Navigator 2.0 to access an IIS server that uses Windows NT challenge/response password authentication, a dialog box appears that requests your user name and password. After you enter the correct user name and password, you see the message "Error: Access is Denied."

Even though Netscape Navigator 2.0 prompts you for a user name and password, it does not support Windows NT challenge/response password authentication.

To correct this problem, use Anonymous access or Basic user authentication in Internet Information Server, or upgrade clients to Internet Explorer version 2.0 or later.

Internet Explorer 2.0 Ignores Size Attribute

Internet Explorer 2.0 does not use the Size attribute of the Select tag on HTML pages properly.

RFC 1866 specifies that the Size attribute indicates the number of selections that are displayed when a user clicks a list box. A user should be able to see the selections by scrolling through the selection list box.

Internet Explorer 2.0 displays more than one list item even when Size is set to 1. If you increase the value of the Size attribute, the list box size grows. However, the size of the list box might not correspond to the setting. For example, with Size set to 1, the list box shows three selections, but with Size set to 5, the selection list box shows only four selections.

To overcome this problem, upgrade to Internet Explorer version 3.0.

Internet Explorer 1.5 Does Not Use Default Selection

Internet Explorer version 1.5 for Windows NT does not automatically select (highlight) the preselected item of an option list in an HTML form. The user must click the Reset button or manually select the item.

Internet Explorer 1.5 Is Unable to Save Files

If you run Internet Explorer version 1.5, you might see the message:

Unable to save C:\Temp\filename. Disk may be full.
The attempt to load ftp:filename failed.

This might be caused by a full disk, as stated in the message. The problem can also be caused by a client browser that does not have a \Temp directory.

To solve this problem, create a directory named "Temp" off the root of the boot drive, for example, C:\Temp.

Browsers Fail to Connect When Using SSL

Netscape Atlas and other browsers that support version 3 of the Secure Sockets Layer (SSL) might fail to connect to Microsoft Internet Information Server when the IIS server is using SSL.

Internet Information Server version 2.0 supports SSL version 2. Newer Web browsers, such as Netscape Atlas, support SSL version 3. When the Web browser connects to Internet Information Server, the browser tries to connect by using SSL version 3. Internet Information Server does not recognize SSL version 3 clients, so the connection is immediately dropped. Clients do not attempt to use version 2 after version 3 is rejected by the server.

To solve this problem, use a browser that supports SSL version 2.

Internet Explorer 2.0 Fails to Connect to SSL-Enabled Internet Information Server

When connecting to SSL-enabled IIS servers, you might get one or more of the following messages:

HTTP/1.0 403 Access Forbidden (Secure Channel Required - This Virtual
Directory requires a browser that supports the configured encryption 
options.)

–or–

Unable to connect to servername

To fix this problem, upgrade to Internet Explorer version 2.01 or later.

Logging Problems

Logging to SQL Server on the Network Fails

Although a valid SQL Server user name and password are entered on the Logging property sheet in Internet Service Manager, they might seem to disappear when you start Internet Service Manager.

This is a problem with SQL Server Login Security Mode set to Integrated. In Integrated mode, the user name and password specified in Internet Service Manager are ignored because SQL Server attempts to use the logon account specified when the computer running the IIS server was started. Because this account probably does not have permission to use SQL Server, Internet Information Server logging to SQL Server fails and the SQL Server log records this message:

failure condition - logon failed because there is no valid user account.

And the IIS server reports the following:

Error: odbc reported an error. The Datasource name "DSN_name" may be 
incorrect. Check the server's event log for details.

To resolve this issue, set the SQL Server Login Security Mode to Mixed. This setting enables the IIS server to access SQL Server for logging. Access to SQL Server by using other access methods is unaffected.

For more information about SQL Server Login Security Mode, see Part 4, "Security," of the Administrator's Companion in the Microsoft SQL Server Books Online.

Time Field Appears Wrong in Log

The Microsoft Internet Information Server log file contains a Time field. This field displays the elapsed time from the start of a request (connect) until the request is finished and the item is about to be logged. The value represents only a checkpoint in terms of millisecond difference.

Application and Script Problems

Testing CGI Scripts

You can use a Perl script to test for the proper installation and execution of Common Gateway Interface (CGI) scripts with Internet Information Server.

Use a text editor to create a file with the following lines of code. Save the file in the /Scripts directory as Hello.pl.

print "Content-Type: text/html\n\n";
print "<HTML>\n";
print "<HEAD>\n";
print "<TITLE>Hello World</TITLE>\n";
print "</HEAD>\n";
print "<BODY>\n";
print "<H4>Hello World</H4>\n";
print "<P>\n";
print "Your IP Address is $ENV{REMOTE_ADDR}.\n";
print "<P>";
print "<H5>Have a nice day</H5>\n";
print "</BODY>\n";
print "</HTML>\n";

After you create the file, configure Perl to run securely with Internet Information Server. Do not locate Perl.exe in any directory accessible by a user. Create a script mapping in the Registry for Perl.exe to enable the script to run by using Perl.

To configure script mapping for Perl

1. Click the Start button, then point to Run. In the Open box, type regedt32.exe and then click OK.

2. Click the HKEY_LOCAL_MACHINE window and locate the following key:

   \System

   \CurrentControlSet
   \Services
   \W3SVC
   \Parameters
   \ScriptMap

3. From the Edit menu, click Add Value.

4. In the Add Value dialog box, enter the value name .pl with the data type REG_SZ.

5. In the String Editor dialog box type the string value

   full path\perl.exe %s

   and click OK.

   This instructs Internet Information Server to interpret all files with the extension .pl by using Perl.exe.

6. To implement these changes, quit the Registry Editor, then stop and restart the WWW service.

7. Test the Perl script with your browser. For example, in Internet Explorer, type

   http://Servername/scripts/helloworld.pl?

Programs Attempt to Download to Client Computers

When you attempt to run a script on a client Web browser, an Unhandled File Type dialog box might appear. It requests that you save the file as a different filename or in a different location (Save As).

The problem is that the /Scripts directory has both Read and Execute access permissions set in Internet Service Manager. To work around this problem, do one of the following:

• Change the access permissions in Internet Service Manager to Execute only.

• Add a question mark (?) to the end of the URL. For example,

  http://myserver/scripts/test.exe?

Programs from 16-bit Compilers Fail to Run

A CGI script compiled with a 16-bit C compiler might fail to run on Internet Information Server.

For example, say you use a 16-bit compiler to compile and build an executable file out of this C language source code:

#include <stdio.h>
void main()|
{
   printf( "Content-type: text/html\n\n" );
   printf( "<BODY BGCOLOR=\"#FFFFF0\" TEXT=\"#0000FF\">" );
   printf( "<TITLE>This is a Test page</TITLE>" );
   printf( "<h2>Hello World.</h2><br>" );
   printf( "<h1><center>End of the test page.</center></h1>" );
   printf( "</BODY>\n" );
}

If you then run the .exe file from the command prompt of Windows NT, the correct HTML output is generated. However, the results will be different if you place the same executable file in the /Scripts directory of the computer running Internet Information Server. If you try to run it from a Web browser by using the syntax.

http:// Server/Path/File.exe?

it fails to generate the correct page.

To correct this problem, use a 32-bit C compiler to compile and build the C language source code. Microsoft C/C++ 4.0 and C/C++ 2.0 are 32-bit C compilers.

REMOTE_USER Variable Is Blank

Microsoft Internet Information Server does not return a user name for the variable REMOTE_USER unless both of the following are true:

• Basic (clear-text) password authentication is used.

• Anonymous access is not allowed. (That is, you clear the Allow Anonymous box on the WWW Service property sheet.)

If you use anonymous authentication, all users are authenticated with the IUSR_computername account, and the variable is not assigned a value by default.

One method of obtaining the REMOTE_USER variable is to create a batch file with the following lines and save it in the /Scripts directory, or a directory enabled in Internet Information Server for execute permissions:

@echo off
echo Content-Type: text/plain
echo.
Set

This batch file lists the environment variables used by Internet Information Server, including the REMOTE_USER variable. The list is returned as an HTML page to the Web browser that started the batch file.

Make sure you have configured script mapping for .bat or .cmd files, as described in the Internet Information Server Installation and Administration Guide.

You run the script from a browser by typing a URL with the syntax

http:// Server_Name /Script

For example, you might type

http://www.company.com/scripts/environment.cmd?

The question mark at the end of the URL is required. The question mark signals the server that this is a GET request, which makes the server return script results rather than downloading the file to the user.

CGI Scripts Return Error

When submitting an HTML form or clicking a link to a script from a Web browser, the following message might be returned:

   CGI Error
   The specified CGI application misbehaved by not returning a complete
   set of HTTP headers. The headers it did return are:
   Can't open perl script "c:\inetsrv\wwwroot\scripts\test.pl":
   No such file or directory

This error is caused by missing or incorrect CGI header information. In this case, the headers are missing because the script file cannot be run. Therefore, the message was displayed instead of the output from the script.

The CGI specification calls for the script file to return at least one header. This header indicates how to fill out the remainder of the HTTP headers as required by that protocol. HTTP also requires a blank line between the end of the headers and the start of the document. Some servers return an error if the blank line is not present. The only headers currently supported by the CGI specification are:

• Content-type

• Location

• Status

For more information about these headers, see the HTTP and CGI protocol draft specifications at http://www.w3.org.

IDC Problems

Troubleshooting Microsoft SQL Server

If an Internet Information Server application cannot connect to SQL Server, it might indicate a problem with the network or SQL Server. You can test Microsoft Internet Information Server connectivity with SQL Server by using tools provided with Microsoft SQL Server. Table 8.3 describes tools included with the Microsoft SQL Server product that can help isolate network problems.
Table 8.3 SQL Server Troubleshooting Tools

SQL Server tool	Purpose	Location
Makepipe.exe	Tests the integrity of the network named pipe services.	SQL Server
Readpipe.exe	Tests the integrity of the network named pipe services.	SQL Server clients
Odbcping.exe	Troubleshoots connectivity to SQL Server through Microsoft ODBC SQL Server drivers.	SQL Server
Isqlw.exe	Queries SQL Server, analyzes the execution plan of a query, and views statistics about the executed query.	SQL Server and clients

For more information about Microsoft SQL Server and these tools, see the Microsoft SQL Server Books Online.

SYBASE SQL Server Does Not Work with Internet Information Server

If you try to connect to a SYBASE® database through an .idc file by using the ODBC drivers included in Internet Information Server, you might see this message:

Error performing query state=01000, error 1225 Microsoft ODBC SQL Server 
Driver DBNMPNTW Connection open Create file 
State = 08001 error = 1225 Microsoft ODBC SQL Server Driver unable to 
connect to data source.

The current Microsoft SQL Server ODBC driver is not certified for use with SYBASE SQL Server.

To correct this problem, use SYBASE SQL Server ODBC drivers. Contact SYBASE Corporation for ODBC drivers certified for use with SYBASE SQL Server. Many third-party ODBC vendors also provide ODBC drivers certified for use with SYBASE SQL Server.

SQL Server Returns 'Not Defined as a Valid User'

You might see the following message when accessing an Internet Database Connector (IDC) script:

Error Performing Query
*[State=3700][Error=18450][Microsoft][ODBC SQL Driver][SQL Server]
Login failed- User: _ Reason: Not defined as a valid user of a trusted 
SQL Server Connection.

This message can appear under the following conditions:

• You are not running SQL Server and Internet Information Server on the same computer.

• You are using Windows NT challenge/response authentication on Internet Information Server.

• You are using integrated or mixed security with Microsoft SQL Server.

• You are not providing the user name or password values in your .idc file.

When the client runs the IDC script, Internet Information Server must determine whether the data source is local or remote. If the data source is defined as Local System, the query is passed to SQL Server on the same computer. If the data source is remote, the computer running Internet Information Server must make a network connection to SQL Server. When Internet Information Server makes the network connection, it does not pass the credentials of the remote user. It passes a blank user name and password instead.

SQL Server does not validate a user without a user name, and returns the message to Internet Information Server. Internet Information Server then passes the results of the query to the client Web browser.

There are two possible workarounds:

• Install SQL Server and Internet Information Server on the same computer. Then set up your ODBC system Data Source Name (DSN) to be Local Server instead of a remote computer name.

• Use Basic authentication instead of Windows NT challenge/response authentication.

Pipe/Connection Busy or Time-out Expired Errors Appear when Using SQL Server

If Internet Information Server connects to Microsoft SQL Server through the Internet Database Connector, multiple error messages can appear as databases are added to SQL Server.

The following messages might be displayed when using the Internet Database Connector to make SQL requests to Microsoft SQL Server, if it has a growing number of databases:

*[State=01000][Error=231][Microsoft][ODBC SQL Server Driver]Pipe busy.
*[State=08001][Error=3][Microsoft][ODBC SQL Server Driver]Connection is busy.
*[State=S1T00][Error=0][Microsoft][ODBC SQL Server Driver]Time-out expired.

These problems can result if the SQL Server configuration parameter Open Databases is set too low. SQL Server 6.0 sets this value to 20 by default. If you add databases to SQL Server until you exceed the configured value, it does not generate an "out of open databases" message in the SQL Server log. Instead, the messages listed above appear when you query the database from Internet Information Server.

To solve this problem, increase the value of the SQL Server configuration parameter Open Databases. For more information on setting this parameter, consult the Microsoft SQL Server Administrator's Companion.

Sources of Troubleshooting Information

In addition to the troubleshooting tools that are described later in this chapter, there are several other sources of troubleshooting information in the Windows NT Server Resource Kit and elsewhere. Table 8.4 describes resources that can help you in troubleshooting your Internet Information Server installation.
Table 8.4 Sources of Troubleshooting Information

Resource	Information
Windows NT Workstation Resource Guide, Chapter 23, "Overview of the Windows NT Registry"	Describes how to use information in the Registry for troubleshooting and configuration maintenance.
Windows NT Workstation Resource Guide, Chapter 25, "Configuration Management and the Registry"	Provides problem-solving techniques that use the Registry.
Windows NT Workstation Resource Guide, Chapter 36, "General Troubleshooting"	Provides troubleshooting information for Windows NT.
Windows NT Workstation Resource Guide, Chapter 21, "Troubleshooting Startup and Disk Problems"	Discusses what you can do to find the cause of problems when your computer fails to complete startup.
Windows NT Workstation Resource Guide, Chapter 38, "Windows NT Executive STOP Messages"	Describes the different kinds of STOP, STATUS, and hardware malfunction messages.
Windows NT Workstation Resource Guide, Chapter 39, "Windows NT Debugger"	Describes how to set up for debugging and use Windows NT debugging tools.
Windows NT Server Resource Kit Messages database	Documents thousands of messages with the probable cause of errors and recommended solution. This includes the STOP messages that appear when the system fails with a blue screen.
Windows NT Help	Contains troubleshooting information for the Windows NT operating system.
Microsoft Knowledge Base	Contains support information developed by the Microsoft Support Network. The Windows NT Knowledge Base is included on the Windows NT Workstation Resource Kit CD and Windows NT Server Resource Kit CD. It is also included on the Microsoft Developer Network (MSDN) CD and the TechNet CD, and is accessible through the Microsoft home page, www.microsoft.com. You can search for all Windows NT Internet Information Server articles by specifying Internet Information Server in the query.
Windows NT Workstation Start Here, Appendix A, "Windows NT Setup Troubleshooting"	Describes how to overcome problems installing Windows NT 4.0 on Intel-based computers.

Using Troubleshooting Tools

This section provides a brief overview of the troubleshooting tools that are available on the Windows NT Workstation and Windows NT Server product CDs and the Windows NT Workstation Resource Kit CD and Windows NT Server Resource Kit CD.

Windows NT Tools

The tools described in Table 8.5 are installed when you install Windows NT Workstation or Windows NT Server.
Table 8.5 Windows NT Troubleshooting Tools

Tool	Purpose	For more information
Event Viewer	Displays the system, security, and application logs.	Chapter 37, "Monitoring Events," in the Windows NT Workstation Resource Guide
Performance Monitor	Measures your computer's efficiency, identifies and troubleshoots possible problems, and plans for additional hardware needs.	Part III, "Optimizing Windows NT Workstation," in the Windows NT Workstation Resource Guide, and Chapter 8, "Monitoring Performance," in Windows NT Server Concepts and Planning
Task Manager	Monitors active applications and processes on your computer, and starts and stops them.	Chapter 11, "Performance Monitoring Tools," in the Windows NT Workstation Resource Guide
Windows NT Diagnostics	Enables you to view hardware information in the Registry, such as currently loaded device driver and IRQ values.	Chapter 36, "General Troubleshooting," in the Windows NT Workstation Resource Guide
Network Monitor	Determines problems during session initialization and problems related to broadcast storms, and troubleshoots packets for transmission problems between computers.	Chapter 10, "Monitoring Your Network," in Windows NT Server Concepts and Planning
TCP/IP Utilities	Verifies and debugs TCP/IP networking problems.	Appendix A, "TCP/IP Utilities," in the Windows NT Server Networking Guide

Windows NT Resource Kit Tools

The Windows NT Workstation Resource Kit and Windows NT Server Resource Kit CDs contain many tools that can be used for troubleshooting. This list shows the tools available:

• Crystal Reports Event Log Viewer

• Device Driver Information

• Dump Event Log

• Find Group

• Obtain Ethernet layer address and binding order

• Task Killing Utility

• Event Logging Utility

• Performance Data Logging Service and Configuration Tool

• Performance Meter

• Performance Tools

• Page Fault Monitor

• Process Resource Monitor

• Process and Thread Status

• Process Viewer

• CPU Usage by Processes

• TimeThis

• Task List Viewer

For information about these tools, refer to the Resource Kit Tools Help and double-click the Computer Diagnostic Tools topic on the Contents page.