Fix BIOS USB Flash Not Working

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What is BIOS flashing

Your BIOS lets your computer check what you have, configure it, and allow everything to run on top of it. If your computer can POST (The very first check that everything is plugged in), you can likely fix any software issue with a keyboard and mouse. If your computer does not POST and can’t get to the BIOS configuration screen (You’ll usually press F2, Delete, or another key), you’ll need to restore to a previous point.

Why do motherboards need BIOS flashing sometimes?

If you’re installing new hardware like a new generation of CPU that your motherboard was released before they even existed, or overclocking and end up pushing something too far, you may need to bring things back from the dead. Many newer motherboards have a USB port and a physical button to restore the BIOS from a file and get it back to a working state whenever something goes really wrong. While simple in theory: Drag a file onto a USB, insert it, and press the button… It doesn’t always go that way.

That’s where this guide comes in. But first: Are we doing things correctly?

RTFM: Read the freaking manual

It’s time. Break out the manual, or download a copy for your exact motherboard. You’ll need to know which USB port to plug into, what button to hold for how long, and what to expect. On my specific ASUS motherboard, it’s right next to the button. The manual skips the most crucial bit of info (or at least I couldn’t see it) - the light flashes to indicate it is starting but if it’s solid, something went wrong. I only found this out after an hour of searching for help. So, if you’re lost: search YouTube for videos of people on your exact motherboard, or at least manufacturer and generation. The more you know about what to expect, the better. This is the start of our possibly long journey.

Downloading the file

Search your exact motherboard name, and click the Support page. You’ll likely find downloads for drivers, the manual and the BIOS file. Download the latest version or a specific version if you know you need an older one. If it’s a ZIP; extract it into your Downloads or Desktop.

Now you’ll need to rename the file. This helps people keep multiple versions in a folder (as the name needs to be the same no matter the version on your USB) to whatever the manual says. Some manufacturers include an EXE to run that renames the file for you.

At this point, you can try to Hail Mary it. Once the file is named correctly, we can place it onto a USB. Plug it into the correct slot on your motherboard. Power it down if it isn’t already, and hold the button. Your USB may flash and go off, the light may flash or go off, or remain solid instead of blinking – Whatever the fail state of the BIOS flash is: you may be sitting around for hours while it does nothing. I mentioned finding videos or more info about how it should look, so we know when it’s not working. If it is in a fail state, unplug the USB, and let’s continue.

What we’ll use

Make sure the USB is empty. This way, we’re not leaving essential documents or images on it - as we’ll be wiping it clean. Every bit of data or files will be destroyed in this process, so ensure the USB is empty.

For this, I’ll use the built-in Windows software tool to prepare the drive: Windows Diskpart. You can use other tools like the SD Formatter Tool, FDISK command in Linux, or BOOTICE. See this guide for more info if you don’t want to follow along.

Prepare the USB

Now for the fun part.

• Open a Command Prompt window or Terminal as Administrator. Enter the Windows Diskpart tool by entering diskpart. Hit enter, and we’re in.
• Type list disk to see all the drives in your computer. You should be able to tell which is which just by the size. If you can’t: Unplug your drive and rerun the command. Plug it in once more, and you’ll see which is correct.
• Now select disk where` is your drive number.
• Enter clean to remove all partitions.
• Leave the window open as we may return here later, assuming things don’t go to plan.

Now that our drive is clean open Partition Manager by searching for it in the Windows Start Menu. You can also do it the slow way by running format fs=fat32 in the terminal - but that could take a VERY long time, especially for large and slow USB drives.

In partition manager, scroll to the bottom of the list - where your USB drive will most likely appear. Look for the black bar, indicating an empty dream with no partitions. This is most likely your USB that we just cleared.

Right-click the empty USB in Partition Manager and select New Simple Volume.... Click through the wizard with everything default until you can choose to format the partition. You will see a File system, Allocation unit size and Volume label input.

• Choose FAT32 from the File system dropdown.
• Leave the allocation unit size as Default.
• Set a name for the USB.
• Make sure Perform a quick format is checked.

Click next, then finish, and it should format. Upon completion, you can copy the correct file and safely eject it. On Windows 11, click anywhere in the folder that’s not a file, and you should be able to click Eject from the ribbon bar at the top of the file explorer. Or, you can check the bottom-right of your Start Bar for a USB icon in the tray icon area. Click it, and then click the USB drive with your BIOS on it to safely eject it. This way, we make sure that everything is done copying, and we can safely remove the media.

Plug it into your motherboard and follow along with the steps in the manual. At this point, everything should work fine.

Assuming it doesn’t work and we’re stuck in a fail state, we can allocate a different size instead.

In the same diskpart window from earlier, after plugging in the USB, enter list disk once more and then select disk <X> once more. Run clean once again, and re-open the Partition Manager.

Locate the drive once more, and right-click New Simple Volume… This time, click next only once so we get to the “Specify Volume Size” screen. Enter 500 next to “Simple volume size in MB” so we can have a small partition, just big enough for the BIOS file. The BIOS file will likely be around 10-20MB, but we’ll have more space just in case the motherboard needs to do anything (it likely won’t).

Next, pick a drive letter and click Next once more. Then we get some options we need to populate.

• Choose FAT from the File system dropdown. This is likely new.
• Leave the allocation unit size as Default.
• Set the name for the USB to nothing. Select all the text and hit delete or backspace.
• Make sure Perform a quick format is checked.

After clicking through to the end, and when it finishes: Open the USB drive in file explorer once more and copy the BIOS file.

Safely eject again. Plug it into your motherboard. Follow the steps specified in your manual and hopefully it should read and complete.

Still nothing?

If you’re still stuck in a fail state, there’s not much else we can do other than make absolutely sure you have the correct files. Even a slight difference in the name of the file you’re downloading or the support page you downloaded the BIOS file from could spell disaster. It needs to be absolutely correct.

You can try an older BIOS version and hope for the best… Otherwise, you’ll need to RMA the board assuming something more is very wrong.

If NOTHING is happening, you don’t see the BIOS, and it’s not posting at all: Check to see if other components are loose, and the usual.

Hopefully, you won’t need to send it back. That could be a long process, but you’ll have a working board in the end.