After messing with PC's for many years I have come up against a problem I simply cant solve. Started with random reboots. When it didn't reboot the mouse froze on the windows login screen. Tried a PS2 mouse and the reboots and mouse feezes remained. Upon reboot windows reported a GPU driver eror. Since then I have formatted, tried 2 USB and 1 PS2 mouse, new motherboard, tried the onboard GFX and a PCIe X800, tried a new PSU, new HDD. The only stuff I havn't tried is memory and CPU although the memory passes memtest+ 100% forever. This kinda leaves the CPU but the symptoms are not CPU related, in fact they tend not to boot if the CPU is faulty. One thing I did notice is a USB windows STOP error during setup but I restarted setup and windows loaded. Still the same problems, mouse freezes, reboots etc. So at this point I am lost. Totally baffled and ready to chuck the lot through the widow. Before I do does anyone have any suggestions? Help or ideas greatly appreciated.