sounds to me like either a hardware conflict or malfunction, or a virus. do an update on your virus scanner and run a system scan, also check your hard disk for errors, and then run a defrag, alot of times these simple matinence steps can fix it. if not then, check you cpu temps, and make sure there not to high if they are high check the heatsink for dusk clogs and make sure the fan is running at top performance, (usualy between 3500 and 5000 rpm)
but to me it sounds like a virus, ive had that problem before, also ive had problems with xp just doing that because it seems to not want to empty the temp folder durring reboots and shutdowns an they clog up my drive. i swithced to win2000 and havent got that error.
but i highly recomend to check for viruses first.
download the free version of AVG antivirus. it can detect alot
of viruses and malaculous files that norton and other scanners miss, espesially the ones in the system volume information.
here is the url
hope i was of help