ATI HD5700 and my screen went black while playing MTW2 and made this real ugly/suspicious sound..had to hard reboot win 7. At first my computer wasn't recognizing the card in BIOS..but after I rebooted again it seems to be working.
This was the first computer I built 6 months back (no real problems). So I could have very well screwed something up but I'm at a loss what to do because I don' t think any previous graphics card has crapped out on my like that before. It was really weird and scary.
How should I proceed to find what's actually going on?
First, verify that the inside of your system is free of dust bunnies and hairballs. While you are in there, make sure all of your fans are indeed turning. Pass close attention to the heatsink/fan on your GPU.
Since you have to remove the cover to do the above, also do what you can to ensure you have max air flow for your particular case. Try to keep cables, wires, etc from being directly in front (or behind as the case may be) of any fans. You want a nice, unobstructed path for air to flow in, through, and out of your system.
Verify that your PSU's fan is also functioning.
Last, if all above are okay, you may indeed have a flaky GPU. It happens, not often, but it happens. BTW, if you are overclocking the card, stop while checking all of these things out. You are trying to stabilize your system at this point.