I build my computer about six months ago. The other day, I turned on my computer, and as windows was loading, the power cut off. I thought it was just a temporary power outage, so i tried to reboot. during the post, before windows started booting, the power cut off again. it has been doing this since then. If i wait a while before i try to boot again, it will get farther before it turns off, and if i power on over and over, it takes less time to turn off every go. I run vista with 2gb of ram, PD overclocked to 3.5ghz, a gforce 8500 with 256 mb vram. I have a 500 watt power supply, and it has worked fine for 6 months, so everything should be getting sufficient power. It is plugged into a surge protecter, so the power outage should not have damaged any of the components. I don't think it is overheating either, becasue the mobo's beep code says that everything was working during the post, and usually the fan keeps the cpu at around 40 degrees C. Can someone please tell me what might be wrong, because i have no idea.