New card not recognized

[astar master]

I've removed all traces of my old nVidia card's software. (My 9500 gave up the ghost not long ago when the fan failed and the GPU burned up) My computer did not recognize the new card, an ATI. I manually installed the drivers from the disk that came with the new card, but the computer refuses to acknowledge that there's even a card connected. The Device Manager can't see it. The cooling fan runs, but the monitor remains stubbornly blank whenever I reboot. It is indeed seated properly, before you ask. My question is this--what might cause a computer to fail to recognize hardware? A BIOS error, maybe? Motherboard failure? Any advice you can give me is greatly appreciated. Thanks in advance! Oh, here are my basic system specs:
ASUS m2n68-am motherboard,

 

[LinkedKube]

Might be a dumb question, but I have to assume the worst in people here sometimes. Does this card require a power source of any kind? 4 or 6 pin connector?

You didn't give much detail on what gpu you have now