well i dont know exactly what that problem is, but to me it sounds like your pc is really screwed up!!!
if i was u i would "clean install" windows xp, this is almost guarenteed to solve your problems
p.s. clean install means format (erase all data on your hard drive) and then install windows xp.
most people dont like doing this, but if you do it once u probably will have a trouble free pc for quite a while
NOTE: BACKUP ALL OF YOUR "IMPORTANT" DATA TO A CD-R BEFORE U DO THIS!!! CAUSE YOU WILL LOSE EVERYTHING ON YOUR C: DRIVE