I have what I believe to be a faulty graphics card causing random reboots to my machine. Unfortunately its plumbed with water cooling and removal is a bit more involved than I would like. Fortunately the reboots are roughly every other day so its 'bearable' until I can risk major work on the computer (I'd like a second machine handy before messing with the water).

I have three cards in the computer (EVGA GTX 580s) and think I've determined it to be the third graphics card causing the reboots (no BSOD, just resets).

My question, is disabling the graphics card in device manager sufficient to test whether the card is causing the reboot? What does disabling a graphics card do on the hardware?