OK there is some confusion on this board about the nForce chipset by Nvidia. The nForce2 is not a video card. Look here for more info.
http://www.nvidia.com/page/mobo.html
The nForce, nForce2 and nForce3 are motherboard chipsets. Like the Intel 845 or SIS 746. So if you have a nForce chipset on your motherboard you would still need a video card or some other chipset on the motherboard for video. Also most motherboards that have built on video do not have an AGP slot. So if you see an AGP slot there is a good chance it does not have a built on video card.
Granamere