Here is more about my system and the problem:

My system:
Athlon 64 2800+ (754)
DFI K8M800-MLVF motherboard
BFG Geforce 6800 (AGP)
SB Live! 24bit
2 x 1gb Corsair value select ram
Haumppage pvr-150

The only driver i installed myself was SB live!, the rest i were done by
windows.

More about the problem:
Crashes seem more frequent upon first start ups in the morning, then
sporadic through out the day.
When it crashes it doesn't restart the computer the screen just freezes and
my usb mouse and keyboard lose power (ie. lights all go off) and the computer
sits there until i hit the restart button.

Hope this helps some
Thanks