Updating motherboard BIOS via DOS

This BIOS update via DOS (no operating system required) procedure is general across many (but not all) PC manufacturers and motherboards, including Dell and Gigabyte.

Setup DOS-bootable USB drive

  1. Download the DOS-flashable BIOS firmware from your motherboard manufacturer e.g. support.dell.com
  2. determine (carefully, as it will be erased!) which device (e.g. /dev/mmcblk0) your USB drive is by issuing this command before and after USB drive insertion:

  3. Format (permanently erase) this USB drive with

     umount /dev/mmcblk0
     mkdosfs -F 32 -n dosflash /dev/mmcblk0
  4. From a Linux PC:

     apt install unetbootin
  5. plug in a blank USB flash drive then:

  6. install FreeDOS 1.0 to the flash drive

Copy BIOS file and update BIOS

  1. Extract/copy ALL the BIOS self-extracted files to the root of your FreeDOS flash drive from Linux.
  2. Insert the USB flash drive into the PC to be flashed
  3. Upon powerup, choose to boot from the USB drive (might be pressing F12 key or via BIOS menu)
  4. Select SAFE MODE FreeDOS – the flash utility will NOT work otherwise!
  5. In FreeDOS prompt, type


    or whatever your update file says to do. The flashing process may take several minutes.


If your PC says

operating system not found

on this DOS USB drive, try it in another PC. If it still doesn’t work, try another model of USB flash drive. For some reason, some flash drives just are not amenable to being booted from.

New dead motherboard?

If your new motherboard seems to be dead out of the box, and you’re sure the power supply is working and connected correctly, you may have a CPU that’s too new for the motherboard BIOS. This happened in summer 2014 for Gigabyte GA-Q87M-D2H with version F6 BIOS–version F7 BIOS was necessary for Haswell Refresh CPUs. I had to put an “old” CPU in to flash the motherboard first.

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Written by Michael Hirsch, Ph.D. //