Thanks for getting back.
I do not know which service pack his had on the original install. Mine is with sp2. His product key is on a sticker on the machine so that's not an issue.
No system restore will not work. When I try to use it from safe mode it tries to reboot. I cannot get past the Xp screen on a normal boot.
I can do a few things in safe mode most of the time but sometimes trying the same thing a second time causes it to reboot.
A couple of times I was told that new hardware had been installed this is why I suspect a driver issue.
It may be tied to the processor. My one PC has the same processor in it. Under device manager each thread is listed as an individual processor and named,ie: pentium 4 2.6 mhz. On his each listing just says pentium processor. It also just may be a bios difference. Mine is a Dell board and his is an Intel.
Thanks for the link I'll give it a go.