PC inactive, need help
I left my house, PC still running and when I came back an hour later, the monitor was on standby. But when I moved the mouse, nothing happened. The PC was still running. I restarted, and still no signal on the monitor. Also, I noticed that my keyboard LED backlights were not coming on as well, which meant that it was not making it through the POST process. Those backlights come on and off during the startup process (USB keyboard). I reseated the ram and the video card, as well as cleared the BIOS with no luck. I am really stuck on this one, I am beginning to think the mobo went out, but I am confused as the PC was still running when I returned. It has been running fine and nothing was odd when I left. Help please! Specs in sig.
EDIT: The OC specs in my sig were not active at the time. I run stock speeds on everything and have for over a year, I only OCed to see what it could do and dropped it back down.
EDIT2: I went to switch my keyboard over to my GFs PC in order to see if the keyboard was even still active and her's suddenly restarted. It at first would start up, but restart itself after a few seconds. After turning it off, and then restarting, the keyboard would light on her rig but, now the monitor was not recieving a signal as well.
I am beginning to think this may be a virus, but I have never heard of one like this. My PC will still not light my keyboard, but the motherboard is not producing any errors.
C2D E6420 2.13, FSB 1066MHz
OCZ SLI-ready 1066MHz 5-5-5-15T
eVGA NF63 motherboard
eVGA 8800GTS 640MB
Sound Blaster Audigy 2 ZS
Windows XP Pro 32 bit
OCZ GameXstream 700w PSU