How to perform clean-boot troubleshooting

Clean-boot troubleshooting is a process that confuses many people, but is really not a difficult as it may seem at first. The Microsoft articles on the procedure are detailed and lengthy. I will present a simpler version that should cover most cases, and refer you to the Microsoft Knowledge Base for the full versions. (See the links at the bottom of this page.) It is important that you have an understanding of the theory behind the process, so I will start with a brief overview.

Overview and Theory

Your computer refuses to boot all the way to your Desktop, hangs when shutting down, or some function is compromised, such as networking. Or perhaps a program that used to work is not working properly. Frequently you can find the problem through the use of clean-boot troubleshooting. Here is how it works:

1) Boot to safe mode and see if the problem disappears. Safe mode is a mode in which only the most basic services and drivers are loaded. Startup programs do not start. If the problem is now gone, we know that it was caused by one of the items that does not start in save mode, so now we only have to find out which of these items is causing the problem. If your computer does not start in safe mode, your problem is probable corrupted system files or data.

2) Determine if clean-boot troubleshooting will find the problem. While in safe mode use MSCONFIG (or a tool such as WinMaven) to set up a clean-boot configuration. In a clean-boot configuration only Microsoft service are run, and startup programs are prevented from launching. Reboot to normal mode in the clean-boot configuration. If the problem is still gone, we can use clean-boot troubleshooting to find what is causing the problem; otherwise we cannot.

Note that in the clean-boot Microsoft services are starting, and drivers are loading. Startup programs are not running. If the problem is gone in clean boot, this means the problem was caused by a non-Microsoft service or a startup item. If the problem is still there, it is must be being caused by a driver or Microsoft service that was not started in safe mode. Logical, right? The point is, if the problem is still there, we are through with clean-boot troubleshooting. (The links at the bottom of this page will help you get started with drivers.) If the problem disappears after clean-booting, we can use the clean-boot troubleshooting procedure to locate the source of the problem.

You may have noticed that I did not consider the possibility that the problem might be with a Microsoft service. I worked as a support tech for Microsoft for four and a half years, and I cannot remember more that a couple of cases where a Microsoft service was the source of the problem. What did happen in a few more cases was that I encountered problems that were caused by something that was dependent on a Microsoft service. These problems are very difficult to resolve, and I do not recommend that a neophyte try it on his own. Get help from a professional technician if you suspect this may be the case, but bear in mind that the problem is far more likely to be a driver.

3) Having determined that the problem is a startup item or non-Microsoft service, we now localize the problem by using the clean-boot troubleshooting procedure as described below. This will be accomplished by selectively turning the various services and startup item on and off, and rebooting to determine the effect.

Tools Used for Clean-Boot Troubleshooting

Configuration utilities such as MSCONFIG and WinMaven control the configuration of your computer by making changes to the registry or files that are referenced by Window when starting up the Windows operating system or logging on a user. This determined which services, background programs and other software features will be started. It is important to note that when a change is made with MSCONFIG or WinMaven and the "Apply" button is pressed, only the keys that control the startup process are changed--the actual configuration of your computer does not change immediately. The configuration will not be changed until the next time you reboot your computer. So clean-boot troubleshooting is a process of continually making changes with MSCONFIG or WinMaven, rebooting to see what the effect will be, then making more changes and rebooting, etc.

Troubleshooting shutdown issues requires two reboots per change. The first reboot causes the most recent changes to take effect, and then you have to reboot again to see the effect of the change when rebooting. When troubleshooting shutdown issues it is really nice to have a fast computer.

Clean Boot Troubleshooting Step by Step

Reboot your computer to safe mode. If your problem involves networking, reboot to safe mode with networking. For instructions on rebooting to safe mode click the following link:
How to Reboot to Safe Mode

If the problem is still present in safe mode or safe mode with networking, you will not be able to use the safe mode (or clean boot) troubleshooting procedure.
Next set up a clean boot configuration with msconfig and reboot to normal mode. For instructions on setting up a clean boot configuration with msconfig click the following link:
How to Set up a Clean Boot Configuration with MSCONFIG

If the problem is still gone, you should be able to determine the cause using safe mode (clean-boot) troubleshooting.
Next we will start to narrow down the cause of the problem

Links

The following explains the basics of clean boot troubleshooting for Windows XP and Vista.

How to perform a clean boot procedure to prevent background programs from interfering with a game or a program that you currently use

The following article explains how to perform clean boot troubleshooting on windows 2000.:

How to perform clean-boot troubleshooting for Windows 2000

In the above article you are directed to use regedit to remove the startup keys as required, a tedious process. It is much easier to use WinMaven or a copy of the Windows XP msconfig to do this. (Do not use a copy of msconfig from Windows 98/ME!) Download the Windows XP msconfig here. Download WinMaven here.

How to configure Windows XP to start in a "clean boot" state

How to perform advanced clean-boot troubleshooting in Windows XP

Microsoft has not yet published a Vista version of the above articles, but the following contains similar information:

How to troubleshoot compatibility problems that affect Internet Explorer 7 in Windows Vista

If you would like a webcast giving detailed information on troubleshooting in general, try the following:

Support WebCast: Microsoft Windows XP: Troubleshooting Startup and Shutdown Problems