Since you guys are wondering, here's how to clean it out.
1. Turn everything off.
2. Open computer case (outside)
3. Look for your video/graphics card
4. Take a can of compressed air (found at hardware stores) and clean the outside of the graphics card. Chances are it's really dusty
5. Put the case back on.
6. Enjoy!
If you're worried you'll break the computer, find a tech geek to help you.