I\'m assuming the motherboard is an 810 chipset, and it has built-in graphics. I do believe there is a separate video card with the same chipset (as far as the graphics go) so it\'s a bit confusing. Either way, you need a different video card to get much out of it. Open up the case and see if there\'s an AGP slot (smaller than a PCI, at the very top of the slots, and a brown color). If so, then most any card will work in your board. If not, you\'ll need to make sure you get a PCI card instead.
The Voodoo5 5500 may be a discontinued board, but for around $100-$150, it\'s a killer video card. Otherwise, look into getting a Radeon or a Geforce (I\'d pick the Radeon myself).