Download CPU-Z. Here is a link to it.
Once you click on it, then click the newest version which is I think 1.35. Then your download will popup. Once you have installed it then open the application and it will look something like this.
You will see some tabs on the top that say like, CPU, Cache, Mainboard, Memory, etc. Click on the tab that says Mainboard and then look to the bottom where it says Graphic interface
then lokk under Version
and it shoudl say either agp or pci, or pci-Express. Tell us what it says under that category.