[zell12]

Is your warenty still valid on your computer's HD? If not, take the side panel off, take out the GFX card, boot your computer, then restart it (if you can plug your monitor in to another slot on the motherboard it should be easy), you just need to get into windows and press ctrl+alt+del and click shutdown using tab or the arrows.

When you get it shut down that way or if you just turn the power off put your GFX card back in and start the computer up and reinstall your drivers (hard to find them off the internet, so many different names X_X), and when thats done, configure your GFX Card properly!