If you remove the card, can you then again boot normally.
Others have run into the same situation:
Cons: Would not allow any of the desktops i have to post with this card installed. tried in 3 different machines with no luck
Cons: This card was DOA. After trying the card in two separate systems,
Cons: Out of the box, this card freezes the computer. IOW, once plugged in, the computer doesn't boot.