In Windows XP there is a Prefetcher component, this shortens the amount of time it takes to start Windows and various programs.  When trouble shooting either Windows or program start-up issues, it might be better to disable the prefetcher, because it runs as a background service while other applications are running or loading.

To disable

Start the Registry Editor
Go to HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Control \ SessionManager \ Memory Management \ PrefetchParameters
Double-click the EnablePrefetcher value (remember the value that EnablePrefetcher is set to!)
Change the Value data to 0 to disable the prefetcher.
Close the registry editor and reboot the computer for the changes to take effect.

When finished troubleshooting/repairing, you can re-enable the prefetcher by changing the Value data to its original value.

Values for EnablePrefetcher are:

0 - no prefetch
1 - prefetch applications only
2 - prefetch boot only
3 - prefetch both applications & boot (default)


It may also be useful to periodically clean up the prefetch folder, as it may contain obsolete links.  The Prefetch folder can be found in the Windows folder on your system drive.  Select all the files, and delete them.  When done, reboot your computer.