I have a GT640. I can get DVI out of that but I would prefer to use the motherboard. It was working for about 20 hours then I shut down the computer and restarted last Wednesday and it has not worked since then. Could it be a motherboard issue. Is there any way to do a hard rest of the motherboard?
Chances are that windows updated and installed the software for your graphics card which enables it after shutdown.
The motherboard DVI won't typically work if you have a graphics card installed unless you create a separate windows profile with the graphics card disabled. You should be using the output on your graphics card. It's there for a reason; it processes graphics better than the inferior graphical processing unit built into your motherboard, the card does not re-route its output back to your motherboard DVI port, the DVI on your motherboard will only use the on board graphics that you bypassed by getting a graphics card.