I had 5830 radeon, while playing the screen would go black for 10 seconds and " display driver has stopped working and has recovered" popup appeared.
I changed the video card to gtx 760, the previous problem remains and I got a new one:
while playing PC randomly turns off and then on after 1.5-2 seconds (yes, I counted)
I tried these:
ran memtest - no errors, took out each ram, pc still turned off
scanned hdd for errors - none
tested for temperature on cpu and gpu - not heating
changed thermopaste just in case
ran driver sweeper, reinstalled drivers
NOTHING helps, i'm going crazy
my motherboard is asus p7p55lx
psu is 950w
Do you have all the power connectors fully inserted into the card?
Have you updated all your drivers to their latest versions?
Have you completely purged the old drivers (if not nvidia)?
If you answered yes to all three of these questions, you likely have a defective piece of hardware. This same sort of thing started happening to a friend after he got his GTX 760, and in attempting to get it fixed, the card actually caught fire. Yeah...
But if you answered "no" to any of those, try to fix that, first.