any number of things from over heating to some sort of bad connection. are you getting any error messages in event viewer?
i have a Pentium IV 2.4 Ghz. PC.
Video card: Geforce fx 5600 256Vram
hard drive: 40 Gb, 5200RPM
Power Supply: 300W
the last drivers for all my hardware.!!
i'm in windows XP SP1, when has passed about 30 minutes, my computer crashes, and then, there's no respond from my computer until i restart it manually.
i have formatted it already and all comes to be the same thing!
what can i do?