Here is a question on the same comp, could low power be a cause? I switched out the current video card which was an ATI 1950xt for an older Ati 850xt, and the comp seems to run fine. Is it possible that I was not getting enough power to the newer card (the older card uses less power) and it caused problems? Or do you think the problem is still there just waiting to strike again?
Ahh seems like it was the card.
I don't think it would have been acting the way it was if it was just the card not getting enough power from the PSU, with the system beeps and all.
If that were the case it would boot up but have limited functionality and crash under moderate stress...or something.