Recently, I was going through a bunch of old computer stuff to repurpose, or fix up and get rid of a few older machines.
One of those machines is an old Intel build with a Gigabyte GA-Z68X-UD3H-B3 motherboard, which had always been slightly problematic when trying to boot from USB, access the BIOS or the Boot Menu. Sometimes repeatedly tapping F12 to get to the boot menu would cause it to simply reboot.

I figured the computer would still be useful to someone for basic tasks like web browsing, email etc. But I wanted to solve the issues with it first. After looking at the Gigabyte website I saw there were several newer BIOS revisions, one specifically mentioned fixing USB booting issues, and another newer one to update to a UEFI BIOS.

Unfortunatly, there is not a lot of good information on how to update the BIOS for this motherboard, likely due to the age of the board. The built in Q-Flash utility would not work with the UEFI update file. After some searching, I saw I needed to create a bootable USB drive and place the files on it, boot from the drive and use the Efiflash file that was included with the bios file in order to update.

One forum post in particular said to boot from the USB then at the prompt enter "Efiflash" then after it loads enter "Efiflash %filename%" where %filename% is the name of the BIOS file, in my case "Z68XUD3H.U1n". This did not work. Next I tried entering Efiflash to start the utility, then at the next prompt just putting in the name of the BIOS update file. This also did not work. Unfortunately, I did not save the errors I got for either method.

Next I thought I would try the FLASHEFI utility. After entering "EFIFLASH" at the command line, the utility started, and automatically started updating the firmware with Z68XUD3H.U1n, I thought I was in business. Then after several cycles of erasing and writing files I got an error. "!!! Fixture is NOT Removed or Switch is NOT set to "ON" !!! Press Any Key to Quit". Fortunately, it did not brick the board, I was able to reboot and try again. Next I tried "EFIFLASH Z68XUD3H.U1n" at the prompt. This also did not work.

In the end, what did work was "Efiflash Z68XUD3H.U1n" at the first prompt right after booting from the USB. This is not what any of the forum posts / guides I read suggested.

At the end of it, after updating to the latest UEFI BIOS, all of the issues I was having are solved. Honestly, the firmware the board shipped with is probably the buggiest motherboard firmware I have encountered.