How to Update Your ASUS BIOS: Step-by-Step Instructions

The basic path: read, prepare, and flash

Updating your ASUS BIOS means downloading a file from ASUS, putting it on a USB drive, restarting your computer into the BIOS menu, and telling the BIOS to install that file. The whole process takes 15 to 30 minutes, though the actual installation may pause for several minutes while your motherboard rewrites its firmware. You do not need special software — ASUS builds the update tool directly into the BIOS menu itself.

The risk is real but small: if your power cuts out during the flash, or if you use the wrong file for your exact motherboard model, the board may not start. That is why you need the right file, a stable power supply, and a USB drive that will not fail halfway through. Most people update without incident, but the stakes are high enough that you should not rush.

Before you start, write down your motherboard model number. Look in Windows Device Manager under System Devices, or restart and press Delete or F2 during startup to enter the BIOS menu — the model name appears on the first screen. You need the exact model because ASUS makes different BIOS files for different boards, and using the wrong one will not work.

Key Takeaways

Find your exact motherboard model in Windows Device Manager or by pressing Delete during startup, because ASUS BIOS files are model-specific and using the wrong one will not install.
read the BIOS file from the ASUS support page for your board, then copy it to a USB drive formatted as FAT32 — NTFS will not work in the BIOS menu.
Restart into the BIOS menu by pressing Delete or F2 during startup, then use the built-in flash tool to select and install the file from your USB drive.
Do not turn off your computer, unplug it, or force a restart while the BIOS is flashing — wait for the "Update Complete" message and the automatic reboot.
After the update finishes and your computer restarts, enter the BIOS menu again and reset to defaults, because some settings may not carry over cleanly.

Finding and downloading the correct BIOS file

Go to the ASUS support website and search for your motherboard model. The model number is usually printed on the board itself, or you can find it in Windows by right-clicking "This PC" and selecting Properties, then looking under Device Manager for System Devices. Write it down exactly — for example, "ROG STRIX B550-F GAMING WIFI" is different from "ROG STRIX B550-E GAMING WIFI".

On the ASUS support page for your board, look for the BIOS section. You will see a list of versions with release dates and file sizes. The newest version is usually the one you want, unless you are trying to fix a specific problem — in that case, read the release notes to see what each version changed. read the file to your computer. It will be a .CAP or .ROM file, usually between 5 and 20 megabytes.

Do not rename the file. ASUS BIOS files have specific naming conventions, and the BIOS menu looks for that exact name. If you accidentally rename it, rename it back to what it was when you downloaded it.

Preparing your USB drive

You need a USB drive that is at least 1 gigabyte in size and formatted as FAT32. The BIOS menu cannot read NTFS or exFAT, so if your drive is formatted in either of those, you must reformat it. Plug the USB drive into your computer, right-click it in File Explorer, select Format, and choose FAT32 from the dropdown. This will erase everything on the drive, so move any files you need elsewhere first.

Copy the BIOS file you downloaded onto the USB drive. It should be the only file on the drive, or at least the only file in the root directory. Do not put it in a folder. Safely eject the USB drive when the copy is done.

Entering the BIOS menu and starting the flash

Plug the USB drive into a USB port on the back of your computer — not a front-panel port, because those are sometimes less reliable. Restart your computer. As soon as it starts to boot, press Delete or F2 repeatedly until the BIOS menu appears. The key varies by ASUS model; if neither works, watch the startup screen for a message that says "Press [key] to enter Setup" or similar.

Once you are in the BIOS menu, look for a tool called "EZ Flash" or "BIOS Flashback" or "Update BIOS". The exact name depends on your motherboard, but it is usually in the main menu or under a Tools tab. Select it, and the BIOS will scan your USB drive for the .CAP or .ROM file. When it finds the file, it will show you the version number and ask you to confirm. Select Yes or OK to start the flash.

The screen may go black or show a progress bar. Do not touch anything. The flash usually takes 2 to 5 minutes. When it finishes, you will see a message like "Update Complete" or "Flash Successful", and the computer will restart automatically. Let it restart — do not force it off.

What to do after the update completes

Your computer will boot normally after the flash. You may see a brief message saying the BIOS has been updated, or the boot may be slightly slower than usual the first time. This is normal. Let the computer finish booting into Windows.

Restart again and enter the BIOS menu one more time. Look for an option called "Load Defaults", "Reset to Defaults", or "Restore Defaults" — it is usually in the Exit menu or under a Tools tab. Select it and confirm. This clears any settings that may not have carried over cleanly from the old BIOS version. Your computer will restart again.

After that restart, your BIOS update is complete. Check that your computer boots normally, that all your drives appear in Windows, and that your internet connection works. If you had overclocking settings or custom fan curves, you will need to set them again, because the defaults reset them.

Troubleshooting if the flash fails or does not start

If the BIOS menu does not find your file, the USB drive is probably not formatted as FAT32, or the file is in a subfolder instead of the root directory. Reformat the drive, copy the file again to the root, and try again.

If the flash starts but stops partway through, or if your computer loses power during the flash, your motherboard may not boot. This is a serious problem that usually requires a BIOS chip programmer or a replacement motherboard. To avoid this, make sure your computer is plugged into a working power outlet, not a power strip that might be switched off, and do not move the computer or unplug anything while the flash is running.

If the flash completes but your computer will not boot afterward, try restarting and entering the BIOS menu again — sometimes the BIOS needs a moment to stabilize. If you still cannot boot, try removing the CMOS battery from the motherboard for 10 seconds and reinserting it. This resets the BIOS to factory defaults and may allow the computer to boot. If that does not work, contact ASUS support with your motherboard model and the BIOS version you were trying to install.

When you should not update your BIOS

Do not update your BIOS if your computer is unstable or if you are not sure whether you need the update. Read the release notes for the new version and see whether it fixes a problem you actually have. If your computer is working fine, there is no reason to update. A BIOS update that goes wrong is worse than a computer that works.

Do not update during a thunderstorm or when your power is unreliable. Do not update if you are in a hurry or distracted. The flash takes only a few minutes, but you need to be present and paying attention the whole time.

Do not update if you have overclocked your CPU or RAM. Some BIOS updates change how overclocking works, and your settings may cause the computer to fail to boot. Update first, then reconfigure your overclocking settings afterward.

Frequently Asked Questions

Can I update my BIOS from Windows, or do I have to restart into the BIOS menu?

ASUS makes a Windows tool called ASUS Update or ASUS EZ Flash that lets you update from Windows without restarting. It is safer than the manual method because Windows can verify the file before flashing. If your motherboard support page offers it, use that instead of the manual USB method.

What if I do not know my motherboard model?

Open Windows Device Manager, expand System Devices, and look for an entry that starts with "ASUS" or your motherboard brand. Right-click it and select Properties to see the full model name. If that does not work, restart and enter the BIOS menu — the model name is displayed on the first screen.

Do I need to uninstall my old BIOS before installing the new one?

No. The BIOS flash tool overwrites the old version automatically. You do not uninstall BIOS the way you uninstall software. Just read the new file and flash it.

How long does a BIOS update usually take?

The read and USB preparation take 5 to 10 minutes. The actual flash takes 2 to 5 minutes. The restart and reset-to-defaults process takes another 5 to 10 minutes. Total time is usually 15 to 30 minutes from start to finish.

Will updating my BIOS erase my files or settings in Windows?

No. The BIOS update only changes the firmware on your motherboard. Your Windows installation, files, and programs are not affected. You may need to reconfigure BIOS settings like boot order or fan curves, but Windows itself will be unchanged.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.