What chip-set is your graphics card, Nvidia or ATI?
>> right click "My Computer"
>> choose "properties"
>> click the "hardware" tab
>> go to "device manager"
>> display adapters
What does it say under display adapters?
If you have an Nvidia card you need to go to Nvidia's website and get the drivers from them. Likewise if you have a card with an ATI chip-set, you will go to ATI's website for their drivers.