If you are wondering what type of card you have in your computer you can right click in open space on your desktop there is often a graphics properties, Nvidia control panel, or such an option if one exists, if you click on that it will often give you information on your video card.
Alternatively you can go to Start ----> Run ----> type in devmgmt.msc and click ok
device manager should show up if you're using either XP or Vista, not sure about Windows 7, then click on the + sign next to "Display Adapters" and that should at least give you a name of the card or the chipset being used by your computer. If you need more information on it, google it.