Motherboard won't read video card?

[siegetank]

I have gotten an EPGA GeForce GT220 and after I hook it to my computer, my computer will not read it. After installing it, the monitor only shows signals to the computer's ports. In device manager, the video card does not show up in the Display Adapter in Device Manager. I do have a 350 PSU with a 12 volt rail (300 and 12 were required) and I believe the video card is seated properly. The hoist to maintain the video card (the plastic piece in the mobo) broke off, but I don't think that is a problem. So I think everything but the mobo I tried differently. It works on other computers so there is no problem with that. Please help! Thank you!

(Other Specs)
Motherboard : HP Foxconn Napa
Integrated: nVIDIA GeForce 7100 / nForce 630i (MCP7)

 

[siegetank]

Is it also possible for a defective PCI E slot?