Chapter 36 - General Troubleshooting

Archived content. No warranty is made as to technical accuracy. Content may contain URLs that were valid when originally published, but now link to sites or pages that no longer exist.

This chapter identifies tools that are available in Windows NT to help you troubleshoot problems. It contains information about troubleshooting hardware problems, and how to use information in the Registry to determine why services aren't working correctly. It also contains an example of using information in the Registry for troubleshooting.

Careful record keeping is essential to successful troubleshooting. You should have records of your network layout, cabling, previous problems and their solutions, dates of installation of hardware and software, and so on, all readily accessible.

Many problems can be avoided with routine virus checks. Be sure to check for viruses before installing or upgrading Windows NT on a computer that is already in use.

This chapter identifies other chapters with troubleshooting help; methodology; provides an overview of Windows NT tools; describes hardware problem-solving; and explains how to identify which services or drivers are working.

Sources of Troubleshooting Information

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In addition to the troubleshooting tools that are described in this chapter, there are several other sources of troubleshooting information:

  • Chapter 23, "Overview of the Windows NT Registry," describes how to use information in the Registry for troubleshooting and configuration maintenance.

  • Chapter 25, "Configuration Management and the Registry," provides problem solving techniques using the Registry.

  • 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.

  • Chapter 39, "Windows NT Debugger," describes the different types of STOP messages. It also contains information about using the Windows NT Debugger.

  • The Messages database, included in this Resource Kit, is another source of troubleshooting information. Here, thousands of messages are documented, with the probable cause and recommended solution to each of them. In particular, the Kernel STOP errors that appear when the system fails (with a blue screen) are documented in the Messages database. Chapter 38, "Windows NT Executive Messages," discusses the various types of messages generated by the Windows Windows NT Executive, and categorizes them by their type and severity.

  • Windows NT Help contains a troubleshooting topic.

  • Appendix A in the Windows NT Workstation Start Here book describes how to overcome problems installing Windows NT 4.0 on x86-based computers.

  • The Windows NT Workstation Start Here book describes Microsoft's AnswerPoint Information Services, which provide easy telephone access to the latest technical and support information for Microsoft products.

    The Microsoft Knowledge Base contains support information developed by Microsoft product support specialists. You can search for all Windows NT troubleshooting articles by specifying winnt and tshoot in the query. The Windows NT Knowledge Base is included on the Windows NT Workstation Resource Kit CD. It is also included in the:

    • Microsoft Developer Network (MSDN) CD.

    • TechNet CD.

    • Microsoft Internet FTP host,

    • Technical Support and Services category on the Web page

Troubleshooting Methodology

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This section discusses approaches for solving problems and presents an example of a troubleshooting scenario. There are three parts to this methodology:

  • Isolating the problem.

  • Identifying whether the action has ever worked properly on this computer, or works properly on another computer.

  • Defining an action plan.

Isolating the Problem

First, try to isolate the problem. What, precisely, is not working correctly? Try to narrow down exactly what you expect to have happen versus what is happening.

For example, if your computer does not complete startup, you need to identify how far it gets, and write down any error messages. On an x86-based computer, if you get an error such as Missing operating system from the system BIOS when you start your computer, the problem is very different than if startup fails after the boot loader (NTLDR) starts. You know that the NTLDR has started when you see the message

NTDETECT V1.0 Checking Hardware . . .

Another way to isolate the problem is to figure out if there are related programs or functionality that works correctly on this computer. If so, what are the differences between what works and what does not work?

Identifying Whether It Works in Other Situations

Has what you are trying to do ever worked on this computer before? If so, something might have changed that affects it. Have you changed hardware or installed new software? Has somebody else been using the computer, and could that person have made changes you do not know about?

If this program or functionality has never worked on this computer, compare the setup and configuration on this computer with the same program on another computer to identify differences.

As an example, identical 624 MB IDE disks are installed on two different x86-based computers. On one computer, 609 MB are available after creating and formatting partitions. On the other computer, only 504 MB are available. If you look at the messages that the system BIOS displays when starting up the two computers, you may see that the computer with 609 MB has a newer BIOS than the other computer. You would need to upgrade one computer's system BIOS, or obtain a third-party translation utility that enables the computer to access the entire disk.

Defining an Action Plan

Try to identify all of the variables that could affect the problem. As you troubleshoot the problem, try to change only one of these variables at a time. Keep records of what you do and the effect of each action.

It's advantageous to develop your plan on paper. Decide what steps you want to take, and what you expect to do based on the results of each step. Then do the steps in order, and follow your plan.

If you see a result for which you have no plan:

  • Go back to the isolation phase.

  • Identify what happens in similar situations.

  • Define another plan.

Troubleshooting Scenario

Here is a scenario that shows applying this approach to an actual problem. A user was trying to upgrade his home computer to a newer version of Windows NT 4.0 (before the final product was available). The user was about half finished with copying files from the CD to the hard disk when a message came up saying that a file could not be copied. This was how the user isolated the cause of his problem.

The user has successfully installed earlier versions of Windows NT version 4.0 on this computer. Since last upgrading Windows NT, the CD has been used to install another program, with no problems.

The user has changed nothing on the computer since the last upgrade, except installing the other program. That program should have no relationship to the problem. Other people can install the same version of Windows NT from CD on similar computers.

The user noticed that the CD-ROM drive made noises like it was spinning faster and then slower just before the error message.

These are the steps that were used to identify and recover from the problem.

Step 1. Check the event log to see if there are any errors logged. The CD-ROM drive was reporting bad blocks on the CD, so Windows NT knew that there were problems.

Step 2. Inspect the CD for dust or scratches. There were no obvious problems on the CD, and the user previously had no problems using the CD.

Step 3. Copy files from the CD manually rather than running Windows NT Setup. The file that caused the error copied fine, but other files on the CD could not be copied.

Step 4. Get another CD of the same build and try to install Windows NT from it. Perhaps there is a problem with the CD itself. Windows NT Setup failed on the same file on both CDs, and manually copying files fails on the same files.

Step 5. Install software from other CDs that have worked on this computer before. The user noted that some work, some do not. The ones that do not work have more data on them than ones that install successfully. Therefore, something must be wrong with accessing data on the later tracks of the CD. Data is recorded on CDs starting on the innermost track. CDs vary their spin rate when reading inner versus outer tracks. Something might be wrong with the motor synchronization spin rate.

Step 6. Look inside the CD-ROM drive for signs of dust or hair that might interfere with proper operation at one end of the read head's range of motion. A hair was found stuck to the read head.

Using Troubleshooting Tools

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

Windows NT Tools

These tools are installed when you install Windows NT Workstation:



For more information:

Event Viewer

Display the system, security, and application logs.

Chapter 37, "Monitoring Events," in this Resource Guide.

Performance Monitor

Measure your computer's efficiency, identify and troubleshoot possible problems, and plan for additional hardware needs.

Chapter 10, "About Performance Monitor," in this Resource Guide.

Task Manager

Monitor active applications and processes on your computer, and start and stop them.

Chapter 11, "Performance Monitoring Tools," in this Resource Guide.

Windows NT Diagnostics

Enables you to view hardware information in the Registry, such as currently loaded device drivers and IRQ values.

"Using the fWindows NT Diagnostics Administrative Tool," presented later in this chapter.

Windows NT Hardware Detection Tool (NTHQ)

Identifies installed hardware and settings for diagnostic purposes.

"Using the Windows NT Hardware Detection Tool (NTHQ)," presented later in this chapter.

Windows NT Workstation Resource Kit Tools

The Windows NT Workstation Resource Kit contains many tools that can be used for troubleshooting. For information about all of the tools available in the Windows NT Workstation Resource Kit, refer to the online Resource Kit Tools Help (Rktools.hlp) and double click each of the tools groups from the Contents page.

Troubleshooting Hardware Problems

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There are three Microsoft products that you can use to help troubleshoot hardware problems:

  • Hardware Compatibility List (HCL)

  • Windows NT Hardware Detection Tool (NTHQ)

  • Windows NT Diagnostics Administrative Tool

Using the Hardware Compatibility List (HCL)

The most common cause of hardware problems is the use of hardware that is not listed on the Hardware Compatibility List (HCL). The HCL included in the Windows NT Workstation Resource Kit lists the hardware components that have been tested and have passed compatibility testing with Windows NT version 4.0. It is especially important for you to refer to the HCL if you plan to use any modems, tape backup units, and SCSI adapters.

The latest HCL is available on:

  • The Web at

  • Microsoft's FTP server at

To avoid problems make sure that you are using a device make and model that is listed on the HCL. If several models from one manufacturer are included in the HCL, only those models are supported; a slightly different model might cause problems. Where special criteria are required for a model to be supported (for example, if a particular version of driver is required), this information is described as a footnote in the HCL. As additional hardware is tested, the HCL is updated. New device drivers and other system components are added to the HCL. The updated list and software are available through the electronic services listed at the end of the HCL.

Using the Windows NT Hardware Detection Tool (NTHQ)

NTHQ is an MS-DOS-based program. The next procedure describes how to run the program.

To run NTHQ
  1. When running Windows NT, insert a blank 3.5-inch floppy disk in the drive.

  2. Run Makedisk.bat from the \Support\Hqtool directory on the Windows NT Workstation product CD.

  3. Leave the floppy disk inserted, and shutdown your computer.

  4. When your computer restarts, you are running NTHQ.

The file Readme.txt on the floppy disk contains details about NTHQ. You can see the same information by clicking the Help button on the NTHQ screen.

These are the three ways that NTHQ is most often used:

  • Print hardware information, save it to a file, and keep the report and file with the other configuration information for your computer. You can use the report when planning to change the configuration.

  • If you are having problems installing Windows NT, you can start NTHQ from the floppy disk and use it for troubleshooting, The Readme.txt file contains troubleshooting tips for installation problems.

  • If you cannot start Windows NT, or have installed new hardware and cannot access it, NTHQ might help you troubleshoot the problem. Because NTHQ enables you to view the hardware that it detects, you can find out if any devices are not being detected. For example, if you have not changed your configuration since the last time you produced an NTHQ report, run a new one and compare the results. If you find a difference, you might have a hardware problem.

Using the Windows NT Diagnostics Administrative Tool

You can use this program to display Registry information in an easily-readable format. Windows NT Diagnostics Administrative Tool enables you to:

  • View information about the hardware connected to the computer.

  • Identify device drivers and services that should be started when you start the computer.

To run Windows NT Diagnostics
  1. Click the Start button

  2. Click Programs.

  3. Click Administrative Tools (Common). 

  4. Double-click Windows NT Diagnostics.

The information that you can view is organized into nine tabs. The next screen shot shows the kind of information that you see when you click the System tab.


These are the tabs that you can select in Windows NT Diagnostics:

  • Version shows operating system and hardware information, such as the number and type of processors.

  • System displays more details about the computer, including the type of processor and the Hardware Abstraction Layer (HAL). The System tab is shown in the preceding screen shot.

  • Display describes the video display and its driver.

  • Drives displays information about the disks connected to the computer, the partitions on hard disks, and network shares.

  • Memory displays physical memory and page file information.

  • Services provides the status of all services and devices. It provides more information than is available by using the Services and Devices options in Control Panel.

  • Resources displays information about IRQs, I/O ports, DMA channels, and memory addresses.

  • Environment displays system and user environment settings.

  • Network displays user and network information.

Other Approaches to Troubleshooting Hardware Problems

If your hardware components are listed on the HCL, and you are still having problems, check that the physical connections are secure.

If you are using a SCSI device, check its termination. Even if you are sure the termination is correct, and you are having problems that could be due to incorrect termination, open the computer case and check again. You should use active rather than passive terminators whenever possible.

Note Terminators are used to provide the correct impedance at the end of a cable. If the impedance is too high or too low, internal signal reflections can take place. These echoes represent noise on the cable, and can corrupt subsequent signals, which can result in degraded performance or data loss.

Passive terminators are resistors with the appropriate resistance value for the characteristic impedance of the cable. Active terminators are slightly more sophisticated electronics that are able to better maintain the correct impedance necessary to eliminate signal reflection.

Verify that the SCSI cables are not longer than they need to be. If a two-foot cable is long enough to connect the device to the controller, do not use a three-foot cable just because you have one available. The acceptable lengths vary depending on such factors as whether you are using basic SCSI, SCSI-2, wide SCSI, ultra-wide SCSI, differential SCSI; the quality of the termination; and the quality of the devices being used. Consult your hardware documentation for this information.

Check your hardware configuration. I/O and interrupt conflicts that went unnoticed under another operating system must be resolved when you switch to Windows NT. Likewise, you must pay much closer attention to CMOS and EISA configuration parameters when using Windows NT.

The Knowledge Base is a good source of information for hardware problems. There are several articles about memory problems, memory parity errors, SCSI problems, and other hardware information in the Knowledge Base.

If your computer crashes randomly and inconsistently, you might have memory problems. On x86-based computers, you can use the /maxmem switch in your Boot.ini file to troubleshoot memory problems. Chapter 21, "Troubleshooting Startup and Disk Problems," contains more information about the /maxmem switch and video problems.

Troubleshooting Using HKEY_LOCAL_MACHINE

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Problems can often be traced to services, device drivers, or startup control data. The Registry key HKEY_LOCAL_MACHINE contains this configuration information, so it is a good place to look for information to solve these types of problems. You have two Registry editors that you can use to look at information in the Registry:

  • Regedt32.exe has the most menu items, and more choices for the menu items. You can search for keys and subkeys in the Registry.

  • Regedit.exe enables you to search for strings, values, keys, and subkeys. This feature is useful if you want to find a specific value or string.

Most of the examples in this section use the Regedt32.exe. You see the following screen when you run Regedt32.exe.


The following table briefly describes the Registry keys.




Describes the physical hardware in the computer, the way device drivers use that hardware, and mappings and related data that link Kernel-mode drivers with various user-mode code.


Contains security information for user and group accounts.


Contains the local security policy, such as specific user rights.


Describes the per-computer software.


Controls system startup, device driver loading, Windows NT services, and operating system behavior.

The HARDWARE and SYSTEM keys are the most useful for troubleshooting.

Note Do not change information in the Registry when you are using it for troubleshooting. Instead, use the options in Control Panel, such as Services, Devices, Network, and SCSI Adapters, to change Registry information.

The Registry information and examples in this section are for a Windows NT Workstation computer that uses the TCP/IP network protocol. It uses a DHCP server to get IP addresses. If your computer has a different configuration, or has third-party device drivers or services installed, the Registry will contain different information.


This key describes the physical hardware in the computer. Since the data in the HARDWARE key is stored in binary form, the best way to view the data is by using Windows NT Diagnostics, one of the programs in the Administrative Tools (Common) program group. See the section titled "Windows NT Diagnostics," presented earlier in this chapter, for more information about the program.

For more information about the HKEY_LOCAL_MACHINE \HARDWARE key, see Chapter 23, "Overview of the Windows NT Registry."


The HKEY_LOCAL_MACHINE \SYSTEM key contains information that controls system startup, device driver loading, Windows NT services, and operating system behavior. All startup-related data that must be stored (rather than computed during startup) is saved in the SYSTEM key. This screen shot shows the SYSTEM key and its subkeys.


The most important troubleshooting information in the Registry key HKEY_LOCAL_MACHINE \SYSTEM are the control sets. A control set contains system configuration information, such as which device drivers and services to load and start. There are at least two control sets, and sometimes more, depending on how often you change system settings, or have problems with the settings you choose. The preceding screen shot shows the following control sets:

  • Clone

  • ControlSet001

  • ControlSet002

  • CurrentControlSet

The Registry subkey HKEY_LOCAL_MACHINE \SYSTEM \Select identifies how the control sets are used, and determines which control set is used at startup. This subkey contains the following value entries: 

  • Current. Identifies which control set is the CurrentControlSet. When you use Control Panel options or Registry Editor to change the Registry, you are changing information in the CurrentControlSet.

  • Default. Identifies which control set will be used the next time you start Windows NT, unless you select Last Known Good Configuration. Default and Current typically contain the same control set number.

  • Failed. The control set that was pointed to by Default when a user last started the computer by using the LastKnownGood control set.

  • LastKnownGood. The control set that is a clean copy of the last control set that actually worked. After a successful logon, the Clone control set is copied to the LastKnownGood control set.

The next screen shot shows the value entries for the Select subkey.


Note The Registry editors each display the Registry in a similar way. The window on the left contains the key and subkey names. The window on the right contains value entries. In the preceding screen shot, one value entry is Current : REG_DWORD : 0x1. In this example, Current is the name, REG_DWORD is the data type, and 0x1 is the value. These terms will be used in the rest of this section.

The values for the value entries in the Select subkey identify which control set is Current, Default, Failed, and LastKnownGood. For example, a value of 0x1 indicates that you should look at ControlSet001 to find the infromation.

In the preceding screen shot, Current and Default are both 0x1. Failed is 0, and LastKnownGood is 0x2.

Therefore, ControlSet001 is the Current and the Default control set. ControlSet001 will be the one modified if you make any changes by using options in Control Panel. ControlSet001 will be used for the Default control set the next time you start the computer.

ControlSet002 is the LastKnownGood control set. If you decide to use the Last Known Good control set to start the computer, Windows NT will use ControlSet002.

For more information about the use of the control sets, see:

  • Chapter 19, "What Happens When You Start Your Computer"

  • Chapter 21, "Troubleshooting Startup and Disk Problems"

  • Chapter 25, "Configuration Management and the Registry"

  • The online help file: Regentry.hlp on the Windows NT Workstation Resource Kit CD.

Finding Service and Device Dependencies

This section describes using information in the Control and Services subkeys to troubleshoot problems with your computer. The next screen shot shows the CurrentControlSet and its subkeys.


When you install Windows NT, it creates the Control and Services subkeys for each control set in HKEY_LOCAL_MACHINE \SYSTEM. Some information, such as which services are part of which group, and the order in which to load the groups, is the same for all Windows NT computers. Other information, such as which devices and services to load when you start your computer, is based on the hardware installed on your computer and the network software that you select for installation.

Each control set has four subkeys:

  • Control — Contains startup data for Windows NT, including the maximum size of the Registry.

  • Enum — Contains the Plug and Play hardware tree.

  • Hardware Profiles — Enables you to define different configurations for your computer and select the one you want to use at startup.

  • Services — Lists all Kernel device drivers, file system drivers, and Win32 service drivers that can be loaded by the boot loader, the I/O Manager, and the Service Control Manager. It also contains subkeys describing which drivers are attached to which hardware devices, as well as the services that are installed on the system.

ServiceGroupOrder Subkey

You can see the order in which device drivers should be loaded and initialized by viewing the Registry subkey HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet \Control \ServiceGroupOrder. Individual drivers that are members of a service group are loaded in the following order:

  • System Bus Extender

  • SCSI miniport

  • Port

  • Primary disk

  • SCSI class

  • SCSI CDROM class

  • Filter

  • Boot file system

  • Base

  • Pointer Port

  • Keyboard Port

  • Pointer Class

  • Keyboard Class

  • Video Init

  • Video

  • Video Save

  • File system

  • Event log

  • Streams Drivers


  • NDIS

  • TDI

  • NetBIOSGroup

  • SpoolerGroup

  • NetDDEGroup

  • Parallel arbitrator

  • Extended base

  • RemoteValidation

  • PCI Configuration

"Service Groups," presented later in this chapter, lists drivers that are in each group.

Services Subkey

The Registry subkey HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet \ServicesService name controls how services are loaded. This section describes some of the value entries for this subkey, with an explanation of their values. The next screen shot shows the subey HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet \Services \LanmanWorkstation and its value entries.


Figure 36.1 The Registry subkey HKEY_LOCAL_MACHINE \SYSTEM

DependOnGroup Value Entry

When a subkey has a value for the DependOnGroup value entry, at least one service from the group must be loaded before this service is loaded. This table shows services that have a value for DependOnGroup. The LanmanWorkstation service, shown in Figure 36.1, has a value for the DependOnGroup value entry.


Depends on




SCSI miniport


SCSI miniport






Network Provider




Parallel arbitrator


SCSI miniport


SCSI miniport


SCSI miniport

DependOnService Value Entry

This value entry identifies specific services that must be loaded before this service is loaded. The "Troubleshooting Example," presented later in this chapter, shows how you can use information in the DependOnService value entry to determine which services need to be started.

This table lists the services on the example computer that have a value for DependOnServices.


Depends on









































By knowing the dependencies, you can troubleshoot a problem more effectively. For example, if you stop the Workstation service, the Alerter, Messenger, and Net Logon services are also stopped, because they are dependent upon the Workstation service. If an error occurs when you try to start the Workstation service, any of the files that are part of Workstation service could be missing or corrupt. This is also why, if you start one of the services that depend on Workstation service, the Service Control Manager will automatically start the Workstation service if it is not already running.

ErrorControl Value Entry

This value entry controls whether an error during the startup of this driver will cause the system to switch to the LastKnownGood control set. If the value is 0 (Ignore, no error is reported) or 1 (Normal, error reported), startup proceeds. If the value is 2 (Severe) or 3 (Critical), an error is reported and LastKnownGood control set will be used.

The ErrorControl value for LanmanWorkstation is 0x1, which indicates that if there was an error starting LanmanWorkstation, an error would be logged in the event log, but Windows NT would complete startup.

ImagePath Value Entry

This value entry identifies the path and file name of the driver. You can use My Computer or Windows NT Explorer to verify the existence of the named file. The ImagePath for LanmanWorkstation is %SystemRoot%\System32\Services.exe.

Start Value Entry

This value entry determines when services are loaded during system startup. If a service is not starting, you need to know when and how it should be starting. Then look for the services that should have been loaded prior to this service. The values are described as follows:






Loaded by the boot loader (NTLDR or OSLOADER)
during the startup sequence.



Loaded at Kernel initialization during the load sequence.


Auto Load

Loaded or started automatically at system startup.


Load On Demand

Driver is manually started by the user or another process.



Driver is not to be started under any condition. If a driver is accidentally disabled, reset this value by using the Services option in Control Panel. File System drivers are the one exception to the Start value. They are loaded even if they have a start value of 4.

Type Value Entry

The Type value entry helps you know where the service fits in the architecture. These are its possible values:




Kernel device driver.


File System driver, which is also a Kernel device driver.


Set of arguments for an adapter.


A Win32 program that can be started by the Service Controller and that obeys the service control protocol. This type of Win32 service runs in a process by itself.


A Win32 service that can share a process with other Win32 services.

Many of the services that have a Type value of 0x20 are part of the Services.exe. For example, if your network protocol is TCP/IP, and you are configured to use a DHCP server to get IP addresses, these services that have a Type value of 0x20 are in the Services.exe:

  • Alerter

  • Browser

  • DHCP

  • EventLog

  • LanmanServer

  • LanmanWorkstation

  • LmHosts

  • Messenger

  • NtLmSsp

  • PlugPlay

These services are part of the NETDDE.exe:

  • NetDDE

  • NetDDEdsdm

Service Groups

Many device drivers are arranged in groups to make startup easier. When device drivers and services are being loaded, Windows NT loads the groups in the order defined by ServiceGroupOrder. The next table shows which drivers are in each group.

Group name






Boot Files System




Event log




Extended Base




File System








Keyboard Class




Keyboard Port
























Parallel Arbitrator




PCI Configuration








Pointer Class




Pointer Port












Primary Disk












SCSI Class




SCSI Miniport



Oliscsi Ql10wnt slcd32
Ultra14f Ultra24f





Streams Drivers




System Bus Extender












Video Init




Video Save




Troubleshooting Example

This section describes using information in the DependOnGroup and DependOnService value entries to find the cause of the following error message that you see after you log on.


You can use the Event Viewer to see which services or drivers did not start.

To run Event Viewer
  1. Click the Start button

  2. Click Programs 

  3. Click Administrative Tools (Common) 

  4. Double-click Event Viewer 

  5. If the screen is displaying a log other than System Log, on the Log menu, click System 

The event log shows the following entries.


Sometimes, as you can see by the preceding System Log screen shot, several events are logged at approximately the same time. In this example, the newest event is entered at the top. Usually, if you look at the oldest event, you will find the reason that all of the events are logged. In this example, the fourth entry from the top was the first one logged at 1:41:24. Double-clicking on it results in this event detail.


But you look in the Registry there is no subkey HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet \Services \Workstation. How do you find it? You have two methods that you can use.

You can use Regedit.exe to find the name anywhere in the control set.

To use Regedit.exe to find the Workstation service
  1. Click the Start button.

  2. Click Run, and enter Regedit.exe.

  3. Double-click HKEY_LOCAL_MACHINE, double-click SYSTEM, double-click CurrentControlSet, and click Services.

  4. On the Edit menu, click Find.

  5. In the Find what box, enter Workstation and check the Keys and Data checkboxes. Clear Match whole string only.

  6. Click Find.

  7. If the match is not what you are looking for, on the Edit menu, click Find Next until you find the correct key.

If you think that the service name is part of the key name, you can use the Windows NT Registry Editor.

To use Regedt32.exe to find the Workstation service
  1. Click the Start button.

  2. Click Run, and enter Regedt32.exe.

  3. Double-click HKEY_LOCAL_MACHINE, double-click SYSTEM, double-click CurrentControlSet, and click Services.

  4. On the View menu, click Find key.

  5. In the Find what box, enter Workstation. Clear Match whole word only and Match case.

  6. Click Find Next.

Both Registry editors find a match on the subkey HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet \Services \LanmanWorkstation. The DisplayName value entry contains the name that you see when you use the Services icon in Control Panel, or the Services tab in the Windows NT Diagnostics administrative tool, to view information about services.

Therefore, this subkey is the one you are searching for. Its Start value is 0x4, which means it is disabled. It should be set to 0x2, which indicates it would start automatically when you start Windows NT.

As it turns out, you specifically disabled the Workstation service by using the Services icon in Control Panel and setting the Startup Type to Disabled. The computer was restarted to see what happened.

But what about the other errors that are in the event log? If you double-click each of the first three entries, you find the following descriptions:

The Messenger service depends on the Workstation service which 
failed to start because of the following error.
The specified service is disabled and cannot be started. 

The Computer Browser service depends on the TCP/IP NetBIOS
Helper service which failed to start because of the following error.
The dependency group or service failed to start.

The TCP/IP NetBIOS Helper service depends on the NetworkProvider
group and no member of this group started.

Changing the LanmanWorkstation service to start automatically will solve the problem with the Messenger service failing to start.

The Computer Browser and TCP/IP NetBIOS errors are both the result of no member of the NetworkProvider group starting. How do you find what services are in the NetworkProvider group? Regedt32.exe doesn't have an option to search for data, so you can use the Regedit.exe to find the NetworkProvider group.

To use Regedit.exe to find the NetworkProvider group
  1. Click the Start button.

  2. Click Run, and enter Regedit.exe.

  3. Double-click HKEY_LOCAL_MACHINE, double-click SYSTEM, double-click CurrentControlSet, and click Services.

  4. On the Edit menu, click Find.

  5. In the Find what box, enter NetworkProvider and check the Data checkbox.

  6. Click Find Next.

The only subkey that has a Group value of NetworkProvider is LanmanWorkstation. Changing LanmanWorkstation to start automatically will also solve these problem.

Identifying a Service or Driver That Doesn't Start

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Some services are configured to start automatically on Windows NT. The specific services depend on your computer configuration, and which network services and protocols you are using.

You can use the Services option on Control Panel to view which services should have started automatically and see which ones did start. For example, the next screen shot was taken when the Workstation service was disabled.


You can see that TCP/IP NetBIOS Helper is configured to start automatically, but it did not start. The section "Troubleshooting Example," presented earlier in this chapter, describes why it did not start.

Sometimes, if a file that is needed to load or run Windows NT becomes corrupt or is deleted, the system displays a message about a problem with the file. You might also get information logged in the event log. You can use the message or the information in the event log to find the problem.

But not all executables or dynamic link libraries report missing or corrupt files, and the symptoms can be unpredictable with a file missing. What do you do if there is no indication of an error, but you think some component did not start correctly?

You can check to see if all the Windows NT system files exist and appear to be uncorrupted. Symptoms of file corruption include a file being an unusual size (for example, zero bytes or larger than its original size), or having a date or time that does not match the Windows NT installation date or dates on service packs that you have installed. You can compare files in your %systemroot%\System32 folder and subfolders with files in these folders on another computer that has the same Windows NT version and service packs installed.

If you think that you might be having a problem with a Windows NT system file, you can run Windows NT Setup and repair the problem by using the Verify Windows NT system files option.

If you can log onto your computer, you can use the Drivers utility on the Windows NT Workstation Resource Kit CD to display information about the device drivers that were loaded. If you have previously printed the output from the Drivers utility (by redirecting the output to a printer or a file), you can compare the previous output with one that you produce when you think you might be having problems with drivers not loading. Another method of determining if there are drivers missing from the list is to run the Drivers utility on a similar computer and compare the results.

This is a description of the output from the Drivers utility. The most important field is ModuleName, which is the name of the component.




The driver's file name.


The non-paged code in the image.


The initialized static data in the image.


The uninitialized static data in the image. This is data that is initialized to 0.


The size of the data that is paged.


Data not needed after initialization.


The date that the driver was linked.

To get a hardcopy of the output from the Drivers utility enter drivers >filename at the command prompt, and then print the file. The next example shows some of the output from a Drivers report.

ModuleName Code Data Bss Paged Init LinkDate
ntoskrnl.exe 265472 39040 0 432128 76800 Mon Apr 15 16:28:07 1996
hal.dll 19904 2272 0 8992 10784 Wed Apr 10 10:24:22 1996
Atdisk.sys 12352 64 0 0 10368 Wed Apr 10 10:30:24 1996
Disk.sys 2304 0 0 7648 1504 Wed Apr 10 10:31:18 1996
CLASS2.SYS 6112 0 0 1472 1024 Thu Apr 11 09:21:58 1996
Ftdisk.sys 22880 32 0 1504 2048 Fri Apr 12 12:00:30 1996
Diskperf.sys 2048 0 0 0 768 Wed Apr 10 10:30:17 1996

Troubleshooting Laptop Problems and Using Laptops

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Windows NT version 4.0 provides a new feature that is especially useful for laptops, hardware profiles. You can have one hardware profile for running your laptop when it is in the docking station, and another one for the undocked situation. When you have more than one hardware profile defined, you select the one that you want to use during startup, from the Hardware Profile/Configuration Recovery menu.

The easiest way to set up the hardware profiles is to install Windows NT Workstation when your laptop is docked. Windows NT Setup installs the network software that you need to use your docking station, and creates a hardware profile called Original Configuration (Current). You can copy this hardware profile, and customize the new hardware profile.

To create a hardware profile for an undocked configuration

  1. Double-click the System option on Control Panel.

  2. Click the Hardware Profiles tab.

  3. If you do not already have a hardware profile for your undocked laptop, copy the Original Configuration (Original). Click Original Configuration (Current). Click Copy, and enter a name for the undocked configuration.

  4. On the Hardware Profiles tab, click the profile for undocked, and click Properties.

  5. On the General tab, check This is a portable computer, and click the Radio button for The computer is undocked.

  6. Click the Network tab. Check Network-disabled hardware profile. Click OK.

You can also use the undocked hardware profile to set a different video resolution for your laptop, For example, your Original Configuration can have the video resolution set to 1024x768 to run on your monitor. And you can change your undocked configuration to use a resolution of 640x480, or 800x600, or whatever size is appropriate.

The next procedure assumes that you have already created a hardware profile for the undocked configuration, as described earlier in this section.

To change the video resolution

  1. Start your computer, and select the undocked hardware profile on the Hardware Profile/Configuration Recovery menu.

  2. Double-click the Display option on Control Panel.

  3. Click the Settings tab.

  4. In the Desktop Area group box, move the slider bar until you see the resolution that you want to use.

  5. Click OK. You can test the new size by clicking the Test button.

  6. Click OK to exit the Display Properties dialog box.

Windows NT does not yet support the following on laptops:

  • Power management. On most laptops, you can configure power management in the CMOS.

  • Hot-swappable PC cards (formerly called PCMCIA). There is a PC Card option on Control Panel, but you cannot insert or remove cards while the laptop is running.