Hi,
What is the amount of RAM installed on your machine?
You may configure the computer in clean boot and check if the issue persists. It will start Windows XP by using a minimal set of drivers and startup programs and helps to eliminate software conflicts.
The following link has steps showing how to perform clean boot: http://support.microsoft.com/kb/310353
Note: Please ensure that the computer is set to start as usual by following the section ‘Steps to configure Windows to use a Normal startup state’ from the article: How to configure Windows XP to start in a "clean boot" state: http://support.microsoft.com/kb/310353
Hope the information helps.
Please post back and let us know.