If your machine's hosed even beyond that, you can boot up another, working motherboard
(preferably of the same model, and at least using the same flash util and chip size), prise
out its bios chip (yes, while it's running), put in the hosed one, and run the bios flash. Done incorrectly, this is a great way to hose two motherboards.
If you know someone with an EEPROM
blower, use that instead. It's much safer.
Finally, if the flash program exits to dos, Don't switch off
or reboot. Run it again while you still can (Especially if it's a laptop... Break them and it's a return to base