hm sounds like your in a bit of a pickle..
to flash your bios - now this is a *very* general guide....
but *generally* (

), make a boot floppy (insert floppy into another pc, right click a drive>format>tick the box that says"make ms-dos boot floppy), then copy like a ecs_flash.exe and bios_update.00 file to the floppy.
boot off of the floppy, and type ecs_flash bios_update.00
now i havent done any research on your specific board, so those steps could be completely wrong, but yeah thats a rough guide...goodluck