Try either Belarc or SIW and see what they say your video card is and post back.
Belarc click here
SIW click here
One thing perhaps I should mention, do you know if you have a seperate graphics card or if its onboard graphics, if its onboard graphics then we'll need to know the motherboard make and model number or if its a branded PC then the make and model of that.
The two programs listed above will give you what you need to know.