|Check all connections that may have loosened.|
Did you ground yourself before touching anything inside the computer case? (static can damage components)
Did you have to use excessive pressure when installing the card?
Are you sure the card and slot are both regular PCI?
If the keyboard is USB, use it on rear port directly on the motherboard, not on an expansion card or front port. Do not use Wireless keyboard since it will only work after Windows drivers are loaded at boot up. If available try a different keyboard, especially a PS2 keyboard if you have one from an old computer.
Try clearing CMOS (see your manual) and resetting Defaults in BIOS after that.
You have to be a little bit crazy to keep you from going insane.