Ahh... IRQL_NOT_LESS_OR_EQUAL
Times I've had that appear:
Unstable graphics drivers
CPU Overheating
You said you'd updated the graphics drivers already, good call. Have you tried falling back to the windows default drivers? (if they exist for your card that is) and see if the problem disappears
As for CPU Overheating, if your mobo has a heat sensor under the CPU you can usually pick up the temp from the BIOS or using MBM (
http://downloads.pcworld.com/pub/new.../MBM__5360.exe)
Jim