Hi,
When exactly do you get this error?
Perform a clean boot to check if a third party application or service is causing the problem. With the help of clean boot we can isolate the conflicting application to fix the problem.
Refer this KB article for help:
How to configure Windows XP to start in a "clean boot"state :
http://support.microsoft.com/kb/310353
Please refer the below mentioned article before posting your question as it can help you to provide all the relevant details pertaining to the issue:
How to ask a question:
http://support.microsoft.com/kb/555375
Regards,Afzal Taher - Microsoft Support. Visit our Microsoft Answers Feedback Forum and let us know what you think.