[Crispy's Critter]

I leave my desktop computer on all the time, and it usually goes into sleep mode after a while, and I wake it up by moving the mouse. I came home after work today, went to wake it up, and nothing happened. I couldn't get it to do anything, so I did the hard reboot thing (which I never do if it can be avoided), but all that happens is it sounds like the fans and everything start up, but the hard drive light just stays on steady, as if it's working constantly. The monitor never turns on, so I can't tell if it's starting at all, but since the HD light never goes off I think it's getting stuck somewhere in startup. I've tried booting from the windows CD, but it won't start from that either. I also wondered if maybe one of the vid cards is fried (running 2 cards in SLI on that machine), which was why the monitor wouldn't turn on, but that light being constantly on makes me think it's something else. Any ideas, advice, or suggestions?

TIA