I have heard that you can update bios using a flash drive. You need it to be in a special format and have all the correct load files on it. I have never done it myself.
You need the bios to to boot into a usb drive/floppy, so depending on what went wrong with the flash, you may have a brick. A bootable usb drive is only useful for flashes that will not function without windows memory managers, not bricked systems.