Flash BIOS Without a Floppy

Flashing the BIOS without a floppy drive can be done with an Ultimate Boot CD (free!) and a USB memory stick. BIOS upgrades usually come in the form of an MS-DOS executable meant to be run from a bootable floppy, but modern computers don’t usually have floppy drives anymore, and who has a copy of DOS lying around anyway?

  1. Download a copy of the free Ultimate Boot CD and burn it to disk. FreeDOS (and a lot of other useful stuff) is preinstalled on the CD. As the name implies, FreeDOS is a free, open source, binary-compatible replacement for MS-DOS.
  2. Download the replacement BIOS from your motherboard’s manufacturer. Unpack it onto a USB flash drive.
  3. Plug your flash drive into the target computer and boot it with your Ultimate Boot CD. Select FreeDOS from the menu.
  4. FreeDOS asks a number of configuration questions while booting. You can usually leave all at their default except for the ASPIUSB driver. ASPIUSB is not enabled by default (at the time of this writing), but is necessary for the use of a USB flash drive under DOS, so enable it when prompted.
  5. If you miss the prompt for the USB driver, don’t worry. Type “menu” at a command prompt and enable USB devices from the popup menu.
  6. Change to your flash drive by typing e.g. R: and execute the BIOS flash utility as per the manufacturer’s instructions. (If you don’t know which drive letter to use, type “menu” and select the option to display active drive letters.)

2 Responses to Flash BIOS Without a Floppy

  1. My USB controller is using a memory address that conflicts with Free DOS memory mapping, as a result the UBCD Free DOS crashes due to a kernel panic when I enable USB detection.

    After many struggles with UBCD, I was able to download a MS-DOS 6.22 ISO which I burned to a CD, booted my machine to A:\> prompt and flashed my bios. I found the DOS & Mindows ISOs here :


    Thank you for your original post.

    • Tried like Baji wrote but A: prompted to insert a disk. Baji or any one cares to help further. Trying to flash an ASRock P4i65G.