As you may know, Windows XP has a memory management component called the Prefetcher. By design, this component shortens the amount of time that it takes Windows and the most often used applications to start up.

In order to accomplish this feat, the Prefetcher goes to work during the startup routine. However, this component can get in the way when you're troubleshooting startup problems.

If this happens, you may want to disable the Prefetcher. Follow these steps:

1. Open the Registry Editor (Regedit.exe).

2. Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\ Control\Session Manager\Memory Management\PrefetchParameters.

3. Double-click the EnablePrefetcher value.

4. In the Edit DWORD Value dialog box, change the Value Data setting from 3 to 0.

5. Close the Registry Editor, and restart Windows XP for the change to take effect.

When you've finished troubleshooting the startup problem, be sure to go back to the Registry Editor, and change the value of EnablePrefetcher back to 3.

NOTE: Editing the registry is risky, so be sure you have a verified backup before saving any changes.