first set bios to optimal defaults, extract new bios to a floppy and delete all files except the .bin file, you should only have 1 file on the floppy the .bin
put the floppy disc in and reboot, as soon as you see post up press ALT & F2 at the same time, this will start the built in flash program, when done flashing remove disc reboot and enter setup and select optimal defaults, DONE!