Oh man, you really need to figure out what video card you have, once you know that, you can download new drivers and things will probably be fixed. Do this to find out what video card you got:
1) goto your desktop
2) right click on the icon that says "My Computer" in the upper left corner of the screen mostly
3) click Properties
4) Now in the second tab in the next screen there should be a list of all the things that are in/on/connected to your computer. There should be one thing in that list that says something like Screen Adapters, click on the little + sign infront of that. Now you should see what your video card is, write that down. If you want more info click on it, and then on the Properties button on the bottom.

Still with me? cool, now you know what you video card is. Try to find the URL of the website of the company that made your card and download the newest drivers from there.

hope that helped