Sudden & Complete Computer Failure

Hello,

Last night I was online on my home PC, hanging out on Facebook, when my screen went black and my computer completely stopped responding - no sound, keyboard, mouse, or monitor. I have a Gateway running XP (not sure of the model number...posting from work). The orange light and the green light on the DVD drive started flashing , three flashes with both and then one flash of just the green light.

When I attempted to restart, the lights came back on, but the keyboard, mouse, monitor, etc. did not. When I switched the monitor off and back on, it said there was no signal from the PC. There was also no beeping to indicate startup, but I usually don't hear the beeping unless I have the speakers on. I tried unplugging everything and waiting a bit before turning it on again, but that didn't help, and unhooking and reattaching the monitor, etc., to the PC didn't seem to help either.

My sister thinks that I might have picked up a virus, but I wanted to see if anyone could tell me if the flashing lights might indicate something else?

Thanks!