How to Upgrade BIOS Without OS

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A BIOS is used to provide communications between an operating system and computer hardware. Without an updated BIOS, newer hardware may not be able to function correctly. You can upgrade your BIOS without having an operating system installed. You will, however, need access to another computer with an Internet connection. Upgrading your BIOS takes around ten minutes, including downloading the update itself. You can upgrade your BIOS by floppy disk, CD or flash drive..


Step 1

Determine the correct BIOS for your computer. As your computer boots, press the correct key, which will be displayed on the initial boot screen, to access your BIOS. Your BIOS is determined by your motherboard manufacturer. The motherboard manufacturer will be listed on the first screen of the BIOS near the top of the screen. Typical BIOS entry keys include F2, Esc and Del.


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Step 2

Download the BIOS update. You will need access to the Internet to do this. You can use a public computer or a friend or family member's computer. The exact download location will vary based on the computer and motherboard manufacturer (see Resources).

You can also visit your computer manufacturer's website, such as HP, Dell, or Compaq, and enter your computer make and model for a list of driver and BIOS updates specific to your computer. Visit the Support section of the manufacturer's website in order to find the update.


Step 3

Choose the version of the update you want to use. For instance, most manufacturers offer BIOS updates for floppy disks or other removable media. Floppy disk updates are still common, but many computers no longer have 3.5" floppy disk drives. Choose to download the removable media version so you can place it on a flash drive.


Step 4

Open the folder you just downloaded, if there is a folder. There will be a ReadMe.txt file. Read this to determine the specific installation instructions for the BIOS upgrade. Some BIOS upgrades require you to unzip certain files and only place a portion of the downloaded files on your installation media.



If there is only an installation file, copy it to a floppy disk, flash drive or CD. The first two are easier and will not require CD burning software.

Step 5

Insert the media with the BIOS upgrade into your computer. Restart the computer and press "F12" to access the boot options menu. (If your computer is already set to boot from your chosen media, you won't have to press F12.) Choose your media from the boot menu to continue.

Step 6

Allow the BIOS update to run completely. Remove the installation media when prompted and allow the computer to automatically restart.


If your BIOS version number is equal to the update you downloaded, you don’t need to upgrade.

Check for BIOS upgrades at least once every two years or after installing new hardware.


Never press any keys or try to turn off your computer during a BIOS upgrade. You can corrupt the BIOS beyond repair, which will prevent any communications between your hardware and system.