I don't think thats your motherboard. Download Belarc and it will tell you click here
Regarding whether the 8800GT will work it depends on 2 things, the 8800GT is a PCI Express card so you need a PCIE x 16 slot not an AGP one as they are not interchangeable and you need a decent power supply. If you look inside your case at the power supply there will be a label on it telling you the wattage. If its 400 watts or less it will need replaced for a more powerful one as graphics cards need more power than they can get from the socket alone.