No video output or frozen garbled image after "welcome" screen

After I log in to windows, it either doesn't output an image at all, or it severely discolors the image. After it does this, I've pressed the power button once, but it doesn't shut down, so it freezes my computer as well. It boots up fine in safe mode, so it's not a hardware issue.

First, I checked if I had a virus, and ran Malwarebytes, but it didn't find anything.

Having installed new drivers the morning before this incident, I tried rolling back the drivers. When that didn't help, I did a clean reinstall of my graphics card, by uninstalling the card via device manager. While this helped me boot normally, I had to reboot my computer after windows automatically downloaded the generic drivers for my card, and I was greeted by my monitor's "No Video Input" message after window's Welcome screen.

I've tried just about every combination of driver uninstalls, safe mode and regular boots, and driver installs. Nothing seems to have any effect, and I'm getting agitated.

I have a GeForce 9800 GT, and Windows 7 64 bit.