Graphics card not detected

My graphics card is not being detected by windows xp. I was using the computer and was installing a windows update when the computer monitor just turned black and the signal got lost. I rebooted the pc but the monitor still didn't receive a signal. I connected the monitor to the onboard graphics plug and went to device manager and the graphics card didn't show up under display adapters. After uninstalling the drivers and updating the bios nothing and I tried reinstalling new nvidia drivers but it says the nvidia setup program cannot locate any drivers compatible with your hardware and it just closes.
Using a 8600gt