Ok so I've been having this problem for the last month, it only happens when I play a game thats graphically demanding, like WoW in some parts, and CoD4 etc...
The problem is that every few minutes my screen will lock up and under CPU% on my G15 it will say 100% for around 5 seconds, I checked in the CPU logging and It was right, spikes to 100% for 5 seconds and it doesn't show what process is causing it.
I've tried virus scanning, updating drivers, under clocking my video card, increasing fan speed, registry cleans.
I'll list my computers specs just in case anyone wants them to try and help:
AM2-940 x2 Dual Core 6000+
ASUS (AM2-940) M2N-X
ECS PCI-E 320MB 8800GTS
2x 1GB DDR2 800
IDE Maxtor 250GB HDD
SHAW Tornade-550 Black Tower Case
Chimei CMV 221D 22" WS Monitor
Vista 32bit
Any help would be greatly appreciated.