Isolating the Source of the Problem

Identify the variables that could affect the problem. As you troubleshoot the problem, change only one of these variables at a time. If you must escalate your issue to a support provider, your detailed notes provide valuable information to the technician who is helping you solve your problem.

For example, if your computer does not complete startup, you need to identify exactly where it fails, and write down any error messages. 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:

Starting Windows . . .

followed by a bar graph. When the bar graph turns solid, the text mode switches to the graphical mode (as represented by the display of the Microsoft Windows 2000 Server Family screen).

For more information about troubleshooting startup problems, see "Startup Process" in this book.

Eliminating variables can help determine the cause of a problem. Do symptoms manifest themselves when you run the system in safe mode? If not, check the programs that run when the system is started normally. Look at the icons stored in the Startup group located in the folder Documents and Settings\ username \Start Menu\Programs\Startup. Pointers to other programs executed at system startup are located in the registry at HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft \Windows\CurrentVersion\Run.



Do not use the registry editor to edit the registry directly unless you have no alternative. The registry editors bypass the standard safeguards provided by administrative tools. These safeguards prevent you from entering conflicting settings or settings that are likely to degrade performance or damage your system. Editing the registry directly can have serious, unexpected consequences that can prevent the system from starting and require that you reinstall Windows 2000. To configure or customize Windows 2000, use the programs in Control Panel or Microsoft Management Console (MMC) whenever possible.

Troubleshooting Ideas

The following are several troubleshooting techniques to help you isolate problems. These include, but are not limited to, hardware and driver compatibility verification, software compatibility verification, and error message analysis:

  • If the problem is the result of a recent change to the system, undo that change. Device Manager lists the device drivers installed on the system. If a device fails and its driver had been recently updated, replace it with the original driver and retest.

  • If an update installed from the Windows Update Web site fails to meet your expectations, restore the original files by running the Update Wizard Uninstall from the Tools menu.

  • If you had no problems the last time the system was started, enter safe mode by restarting the computer and pressing F8 at the Starting Windows screen. When the Windows   2000 Advanced Options menu is displayed, select Last Known Good Configuration to restore the system configuration to the last known working version. Restoring a previous system configuration results in the loss of any changes made in the interim.

  • If you find that there are additional programs executed at startup that are not listed in either of these locations, your computer might be controlled by Group Policies. For more information about policies, see Windows 2000 Server Help. If the computer is on a network, logon scripts or system management applications might also start programs on your computer as you log on to the network.



The Plug and Play specification allows an operating system to disable devices at the hardware level. For example, if you disable a COM port in Device Manager, you might be required to enter the CMOS or system setup to re-enable it.

Test each modification individually to see if it solved the problem. Make note of all modifications and their effect. This information is useful when troubleshooting problems with support personnel, and it provides an excellent reference for future troubleshooting.

Hardware and Driver Compatibility

Make sure that all hardware and drivers are compatible with Windows 2000. Many problems are related to defective or incompatible motherboards, memory, drives, and drivers. Before adding hardware or drivers to your Windows 2000 system, follow the guidelines listed here:

  • For new hardware and new drivers, install Windows 2000 on a single system by running the Windows 2000 Setup CD. Test all hardware for complete functionality on this single system before preinstalling multiple computers.

  • See the Hardware Compatibility List (HCL) and "Designed for Microsoft Windows" hardware logo program information. For more information, see the HCL link on the Web Resources page at .

  • The safest, most reliable drivers to use with Windows 2000 are those that have been tested and signed by Windows Hardware Quality Lab (WHQL). For information about driver signing, see the Windows Hardware Quality Lab link on the Web Resources page at .

  • See the hardware-related readme files provided on the Windows 2000 Setup CD.

Software Compatibility

Make sure that all preinstalled software is compatible with Windows 2000. Certain problems can be related to software that doesn't work well with Windows 2000 or that has an installation routine that is not easily adapted to the preinstallation process.

Install Windows 2000 on a single system by running Windows 2000 Setup from the product CD. Install and test all software for complete functionality on this single system before preinstalling on multiple computers.

Viruses and Error Messages

Check for viruses and see error message documentation. Many problems are related to unexpected errors or system failures. For example, the computer stalls, general protection faults occur, and so on.

  • If protection faults are occurring or the system is failing with Stop messages, check the Knowledge Base for documentation about error messages.

  • Run virus-checking software on the reference system, network reference system, and target computers. It is recommended that regular virus checks be scheduled for all systems as a preventative measure. For more information about virus protection, see "AVBoot" earlier in this chapter.

Test the Affected Feature

Sometimes a single component is behaving incorrectly, such as giving error messages whose origin is cryptic or failing under conditions that cannot be duplicated. If you cannot pinpoint the problem, you might want to try a few tests on the component to gather additional information. Following are examples of tests that can help pinpoint a problem with a component:

  • Make sure the component gives correct responses for valid inputs.

  • Make sure the component gives incorrect responses for invalid inputs.

  • Follow the data. As the data moves from one component to another, examine the inputs and outputs to see if you can determine where the error happens.

  • Use a different set of inputs to see if the problem still occurs. Put together a file that produces a simple known output, and try the test again.

  • If there is more than one computer involved, use independent means to test whether the computers are connected.

  • If you can, check the installation to make sure communication is established between processes.