How to update your BIOS without a CPU

CG Director Author Alex Glawionby Alex Glawion   /  Updated 

If you’re building a new computer and can’t turn it on, you may need to update the BIOS.

Although your CPU is physically compatible with the motherboard, the system will not POST (Power On Self Test = all hardware is OK) until you update the BIOS.

Your system might turn on, but your screen will stay completely black because the motherboard doesn’t know how to communicate with the CPU.

This happens because older motherboards might not have the supported BIOS out-of-the-box necessary for newer CPUs that were released after the motherboard was.

Now you may be wondering: How do I update my BIOS if I don’t already have a compatible CPU to update my BIOS with?

Luckily, you’re not alone and most Motherboard manufacturers have come up with a solution to this problem.

Check to see if your motherboard is made from one of these manufacturers:

  • ASRock
  • Asus
  • Gigabyte
  • MSI

If it is, you’ll be happy to learn that the majority of these motherboards come with a feature called ‘BIOS Flashback’. This allows you to update the BIOS without a CPU through a feature called BIOS Flashback.

What Is BIOS Flashback?

What Is BIOS Flashback

BIOS Flashback is a feature found on certain motherboards that lets you update the BIOS without needing a CPU, GPU, or memory installed.

However, the BIOS Flashback feature can be named differently depending on the manufacturer.

  • ASRock motherboards: BIOS Flashback Button
  • Asus motherboards: USB BIOS Flashback
  • Gigabyte motherboards: Q-Flash Plus (not to be confused with Q-Flash)
  • MSI motherboards: Flash BIOS Button (not to be confused with M-Flash)

Flashing the BIOS is just another way of saying updating the BIOS.

Check the spec sheet of your motherboard on the manufacturer’s website and find if the motherboard offers BIOS Flashback.

This feature will typically be seen under the ‘Special Features’ section of the spec sheet.

The process of a BIOS Flashback is to simply download the BIOS Update File for your motherboard onto a USB flash drive and insert it into the correct USB Port on your motherboard.

You can then press the BIOS flash button on your motherboard to begin updating it.

However, following all the steps listed below is essential to ensure you don’t accidentally brick your computer.

What Type of USB Drive Should I Use for BIOS Flashback?

Although it’s not a guaranteed issue for everyone, there have been multiple reports of PC builders facing issues when using a USB 3.0 flash drive.

After they switched to a USB 2.0 flash drive, the BIOS update worked.

Therefore, I recommend using a USB 2.0 flash drive when you’re flashing your BIOS.

Some manufacturers even state to use a USB 2.0 drive as the motherboard can have difficulty recognizing a USB 3.0 drive.

There is no strict requirement in terms of what size USB drive you should use.

Any size from ~128MB up to 32GB will be fine because the BIOS update file will be small (typically around 10 to 25 megabytes).

If you’re having trouble determining if your flash drive is USB 2.0 or USB 3.0, look at the color on the end connector.

Blue end connectors indicate that the flash drive is USB 3.0, while black end connectors are USB 2.0.

How To Update the Bios Without a CPU (Step-by-Step)

Let’s discuss how to flash your BIOS from start to finish.

I understand how frustrating it is not to be able to use your computer.

This is why I’ll explain each step in detail and make it as easy as possible for you to understand.

Step 1. Find Your Motherboard on the Official Manufacturer Website

The first step is to download the BIOS update file from your motherboard manufacturer’s website.

Make sure you’re on the official website. Never download a BIOS file from anywhere other than the ASRock, Asus, Gigabyte, or MSI website.

The easiest way to find the correct BIOS update file is to search for your motherboard model on Google, followed by the word “BIOS”.

For example, type in “Asus ROG Maximus XIII Hero BIOS” if you have this motherboard.

Motherboard Model

Source: ROG ASUS

It should be the first link that comes up and take you to the manufacturer’s official website. Be sure not to click any paid ads/listings that may appear above it.

Once you’re on the page, double-check to ensure it’s the exact motherboard model you have.

Some models can have remarkably similar but slightly different names.

Step 2. Download the Newest BIOS Update

On the motherboard’s page, you should see a BIOS section with the latest version listed under it.

There will also be a download button next to the newest version.

If you’re having trouble finding the BIOS section, look for a section that says ‘Drivers and Utility’. You can likely find BIOS there.

Click the download button and begin downloading the latest BIOS update for your motherboard.

Step 3. Extract and Rename the BIOS File

Once the download is finished, it will likely be compressed into a ZIP folder.

You’ll need to right-click the file and then press ‘Extract All’ and save the extracted file to somewhere you’ll remember.

Extracting BIOS file

This is typically your desktop or a designated folder.

The next step is to rename the BIOS file.

Renaming BIOS File

For ASUS motherboards, the extracted folder will have a tool that’s called ‘Biosrenamer.exe’.

Simply run the tool, and your BIOS file will be automatically renamed.

You’ll need to rename the file manually if you have an ASRock, Gigabyte, or MSI motherboard.

Rename the BIOS file as follows:

  • ASRock motherboards: rename to creative.rom
  • Gigabyte motherboards: rename to gigabyte.bin
  • MSI motherboards: rename to msi.rom

Although the spelling needs to be accurate, the capitalization doesn’t matter.

You may also see a warning sign that pops up, which states that renaming the file might make it unstable.

Simply confirm that you want to continue renaming the file and disregard this warning.

Step 4. Format the USB Drive As FAT32 and Add BIOS File

The next step is to plug in your USB flash drive.

Before transferring the BIOS file, you’ll need to format the USB drive type.

Find your USB flash drive in the ‘File Explorer’ or under ‘This PC’.

Now right-click the drive and click ‘Format’. Select ‘FAT32’ as the format type to confirm the edit.

Formatting USB for BIOS(FAT32)

Your flash drive must be formatted as FAT32 and not NTFS.

Using an NTFS-partitioned flash drive won’t work as you’re trying to update your BIOS without a CPU.

You can then transfer the BIOS file to your flash drive from your computer.

Step 5. Safely Eject USB Drive

Once you’ve changed the USB drive format type to FAT32 and transferred the file to your flash drive, it’s time to eject the USB drive.

You can complete this by right-clicking the drive in File Explorer and then clicking ‘Eject’.

Eject USB

You can also find an eject button on the bottom right of your Windows screen.

Pulling out your USB drive without ejecting it first can potentially damage your flash drive or corrupt the file inside.

Step 6. Connect Your Power Supply Unit (PSU)

Now get your power supply and connect it to your motherboard.

Both the 24-pin main motherboard power connector and 8-pin CPU power connector need to be connected.

Connecting Motherboard for BIOS update

To complete the BIOS update, you need to connect the CPU cable to your motherboard even without having a CPU installed.

After the two cables are appropriately inserted into your motherboard, connect your computer to a wall outlet and flip the PSU switch to ‘ON’.

Step 7. Insert USB Drive and Press BIOS Flash Button

You won’t need any parts installed on your motherboard except the two power supply cables: 24-pin and 8-pin.

No CPU, GPU, RAM, or SSD is required to flash your BIOS.

At this point, your computer should be on and running.

Locate the USB port on the back of your motherboard that’s labeled ‘BIOS’ or something similar and generally located right next to the BIOS Flashback button.

This is a special port that’s built for updating your BIOS with a USB flash drive.

Ensure your power supply is turned on and running.

Then, insert the USB drive into the special USB port.

Now press the small BIOS flash button located somewhere near the USB port. This button may be called ‘Q-Flash Plus’ on Gigabyte motherboards.

BIOS Flashback Button

Image-Credit: Asus

The button may be on the actual motherboard itself and not on the rear next to the USB port.

Furthermore, you may need to hold the button for around three seconds.

Step 8. Confirm the Update Worked and Remove USB Drive

You will see an LED light appear once the BIOS update starts to work.

The light will begin blinking or flashing.

If you don’t see an LED light, the update likely hasn’t begun. This usually signifies that something is wrong.

Check if:

  • The USB drive is plugged into the correct port
  • The power supply cables are plugged in all the way
  • The power supply is turned on
  • Your BIOS File is named correctly and is located in the root path directly on the USB drive

You should also try holding down the BIOS flash button for three or more seconds if an LED light doesn’t appear.

The LED light will continue flashing or constantly showing until the update is complete.

Once the update is finished, the LED will turn off, and the motherboard may restart or shut itself down.

Now you can remove the USB flash drive and unplug the power supply from the wall.

Then it’s time to install all your PC components to see if your computer is now working.

Once all the parts are installed, you should now be able to see an image on your monitor that shows the computer is working, and not just a black screen.

How Long Should The BIOS Update Take?

The BIOS update should take less than ten minutes to complete.

It usually takes just a few minutes to complete flashing.

However, I recommend waiting up to 30 minutes before trying to fix anything.

If it’s been updating for over 30 minutes or an hour and the LED is still blinking, you might have one of the following issues:

  • Not formatting the USB drive as FAT32
  • The motherboard can’t recognize your USB drive (use USB 2.0 if you’re using 3.0)
  • The BIOS file wasn’t named properly
  • Not following the correct order of completing the BIOS update

The best plan of action is to restart the entire process with a different flash drive. Make sure to follow each step exactly as I detailed it.


Although it can be annoying having to update your BIOS before you can use your new CPU, the process is relatively straightforward.

By following the steps outlined in this guide, your computer will be up and running in no time.

Remember, newer CPUs may require your older motherboard to have the latest BIOS version.

Even if your motherboard is ‘new’, there have likely already been BIOS updates since the motherboard came out.

So if you’re faced with a black screen when you turn on your computer, you now know how to update BIOS without a CPU.


Is the BIOS Flash Process Complete When the Flash BIOS LED Stops Blinking?

Yes, this indicates that the update is completed.

The LED should have been blinking for five to six minutes.

If the LED only blinked or displayed for a few seconds, the update did not work.

What if My Motherboard Doesn’t Offer BIOS Flashback?

If your motherboard doesn’t offer a BIOS Flashback feature, the best method is to install an older, compatible CPU in your motherboard.

You can then use a traditional method to update your BIOS.

If you don’t have another CPU you can install, ask a friend to see if you can borrow one of their old ones.

Another option is to bring your PC into a store and ask them to install a temporary CPU to update your BIOS.

Over to You

So, are the questions in your head regarding updating BIOS without a CPU answered in this article? If you have any questions, feel free to ask us in the comments or our forum!

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Alex Glawion - post author

Hi, I’m Alex, a Freelance 3D Generalist, Motion Designer and Compositor.

I’ve built a multitude of Computers, Workstations and Renderfarms and love to optimize them as much as possible.

Feel free to comment and ask for suggestions on your PC-Build or 3D-related Problem, I’ll do my best to help out!


Also check out our Forum for feedback from our Expert Community.

Leave a Reply

  • Edward

    i have a ASRock a320m-HDV 4.02 with bios version 3.70 i had a ryzen 3 processor in it that came from skytech gaming.. i was recieving error messages such as Memory error or a Kernal error or it would just kick out to the bios settings… i removed and reinstalled the ram… and i have purchased a Ryzen 5 5000series Zen3 architecture and still nothing.. i tried purchasing and installing a Nvidia RTX 2060 card and installing it to see if i would get picture and still nothing. ihave no idea what to do from here and i am curious about the compatibility of the Processor i bought to the ASROCK A320M-HDV i have…

    • Alex Glawion

      Hey Edward,
      Did you ever do a clean OS install?


  • Ali

    Hi there, I installed a new 5600 Ryzen on x570 but monitor mouse keyboard stoped working, I changed it back to same 2600 Ryzen but whole PC turns on but no display mouse or keyboard lights working

    • Alex Glawion

      Hey Ali,
      When did the monitor, mouse, keyboard stop working – When you were booted into the os already?

      With the 2600, does it POST, are you getting any indicator LEDs on your motherboard?


  • Camiel

    Saved me, thank you!