You may be able to isolate the problem using "clean boot" techniques.
http://support.microsoft.com/kb/929135 << written for Vista, but applies equally well to XP
But also upload the minidump as detailed below.
I can run a debugging utility on the dump files if you do this:
1 > create a new folder on the desktop and call it "dumpcheck" or whatever you like
2 > navigate to
c:\windows\minidump and copy the last few minidump files to that folder. *this assumes 'c' is your boot drive, if it is not, subsitute accordingly
3 > close the folder and right click on it and select
Send to Compressed (zipped) Folder.
4 > use the "manage attachments" in the "advanced" reply window to upload that zip file here as an attachment.
This might point us to a 3rd party driver causing the error, if one exists for it.