Flashing a Corrupted bios when the alternate bios still works

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Active member
Mar 14, 2012
Now that many motherboards are coming out with a back up bios, many people are asking about how to flash the failed bios. (BIOS A & B)
All you need to do is download the bios you want to flash, then using a fat32 formated usb stick, run the forum bios flashing tool.
>>Use the MSI HQ Forum USB flasher<<
Do not begin this process unless your computer is 100% stable! Many bios failures are due to faulty ram etc, if you corrupt your "good" bios the board is dead!
1.) Remove any overclock you have.
2.) Boot using the working bios, with the memory stick inserted into the usb port.
3.) As soon as the flashing tool screen comes up and you need to input,reach down and switch to the nonworking bios. (DO NOT SWITCH FROM BIO A TO B UNTIL THE FLASHING TOOL HAS LOADED)
4.) Proceed with FLASH.

*This relates and has been tested on all mainboard with a true hardware switch. Z77a-gd80, M-Power, Big Bang X-power, X79a etc)
Note: If you use the above process with a z77a-gd65, it will appear that it has worked. The bios won't ACTUALLY switch unless the system is powered down. IE You will have it set to bio "b" after a power down and flash the bios. You then re-boot and switch to bios "A" and flash. In reality, you have just re-flashed bios "B" and wont see the difference until you actually power down the system. A re-boot will not switch the bios's!

Process for P67, Z68 and z77a-gd65:

Since the P67 & Z68 both have automatic software switches that operate their dual bios's, the process is a bit different.
If you want to flash both bios's or you see the led indicator showing a corrupt bios, you do a normal bios flash with a single extra step.

After a standard bios flash/ you realize one of your bios's are corrupted, enter bios and navigate to the security section and enable multi bios flashing.  Save & Exit, and the board handles the rest.

Note: This will NOT work if you want to flash backwards. Multi bios update will flash to the most recent version installed. So if you have the P67 & Z68 make sure you don't flash your backup bios unless you are really sure you like the new one.
In the case of the z77-gd65 you are still able to achieve this, but you must flash your bios, power off the machine, switch the bios switch then flash again.

Z77A-GD65 Update:

In regards to the Z77A-GD65, it appears that the only bios the has a properly working multi bios update is version 10.5.
I would recommend to most of you to flash you bios "B" to this bios for recovery if nessesary. I am sure this will be corrected, but for now this seems to be true.

Also to note, you should always keep your back up bios at the earliest stable bios version so that it is a fail safe. Flashing both bios at the same time is really counter productive.

Update: 06/07/2013

All new release mainboards (Z87) with multiple bios's are equipped with a true hardware switch. So the same process to recover a faulty bios remains the same as Z77a-gd80 onward.
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