Are you comfortable opening the computer to look at the graphics card? You can also look in Device Manager and look under Display adapters.
Click on Start
Click on Settings
Click on Control Panel
Double click on the System icon
Click on the Hardware tab
Click on the Device Manager button http://www.computerhope.com/issues/ch000833.htm#01
You could also run "dxdiag" by click on Start and then clicking on Run and typing the command "dxdiag" without the quotes. Once it has run click on the Display tab. It will give you information about your graphics card.