The last week or so, I 've been having a problem where my PC will suddenly shut off very abrubtly, like flicking a circuit breaker... It does not try to reboot automatically, but always reboots without an issue following this random shutdown.

I don't get any message from winxp asking if I want to restore from last known config, etc... it will just do a normal boot once I hit the power switch after failure....

My fist inclination is a possible PSU failure... Running an OCZ psu... the rails appear to be ok when I peek at the voltages within the bios screen.....

Any other ideas as to what can be causing this ? Power Switch, Virus, short on board, etc.????