How to Unlock a BIOS Lock on Desktop PC?

Even an amateur computer technician has good knowledge about how to unlock BIOS passwords on both desktops and laptops. Read this article and learn how to unlock a BIOS lock on desktop PC using few methods explained here.

Sometimes this step is important in order to change some BIOS configurations. You will be denied access to configuration-related information once the password is set and you don’t know the password.

Unlock a bios lock on desktop PCs is a very common practice these days, as several people are going for second-hand system and the previous owners don’t give the password-related information to the new buyers.


  • The simplest way to unlock the BIOS is to disconnect the cables and remove the battery of the motherboard for a few minutes.
  • Clearing the CMOS jumper located on the motherboard is also another useful way to unlock the BIOS.
  • Booting into Windows or from CD/USB as well as using other tools will also help in the process.

How to Unlock A Bios Lock On a Desktop PC?

Unlock A Bios Lock On Desktop PC

The most commonly known method of unlocking a BIOS lock is to disconnect the cables and remove the motherboard battery for a few minutes.

However, there are other ways to accomplish the same task. If there is a CMOS Jumper on your computer motherboard, clear it.

This is an effective method for few laptop and most desktop computers. This is because, the manufacturers often use a battery to sustain the BIOS settings.

As soon as you cut off the power, the BIOS password gets lost forever.

If you fail to unlock your desktop’s BIOS security password by cleaning the CMOS Jumper or removing the battery power, here are some other effective options to try out. Read more about how to assemble a desktop pc.

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Generic Backdoor Default Password

Generic Backdoor Default Password

Just pause for some time and try if any of the most popular passwords works for your computer.

If they turn out to be ineffective, you can always use those tools for password unlocking and resetting. Learn list of default bios passwords.

Try To Boot Into Windows

CMOS De-Animator

If you are an experienced technician and believe in updating your knowledge, you have surely heard about CMOS De-Animator.

There are several BIOS resetting tools but CMOS De-Animator is a wonderful and new-age tool to serve your purpose.

It can easily unlock the BIOS password from within Windows. This tool already has multiple versions and make sure to go with what matches your Windows operating system.

Run the tool as Administrator. How to do that? It’s very simple. Just right click and select ‘Run as administrator’.

Next press ‘Enter ‘on the ‘Proceed’ button and restart your system. After your computer restarts, a CMOS checksum error will be shown on the screen.

It will allow you to access BIOS even when you don’t know or remember the password.

CMOS De-Animator invalidates the checksum of your computer’s CMOS memory and as a result, all settings are set to default values and any BIOS password is removed following a system reboot.

CMOS De-Animator has an option for basic backup and restoration, thereby adding to your computer security.

The stored files will have a .dea extension. However, the program may create some problems on the laptop.

To know how it can create troubles, the laptop owners should go through the author’s warnings.

One negative side of CMOS De-Animator is it sometimes generates false positives in antivirus software. Know How To Clean Your PC Windows Registry.

Try To Boot From CD/USB

Boot cd

If Windows is not booting properly and you are unable to access the BIOS setting for boot order change.

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You are still not unlucky as booting from CD or USB is often a higher priority than doing it from Windows.

The process is also much simpler. You just need to use a flash drive or CD for automatic booting.

However, booting to CD or USB could find a mention below the hard drive in the order and in that case, you need to disconnect it temporarily.

If you have no problem to access Windows, you can use Plop Boot Manager to enable CD/USB booting.

It allows booting from these devices even if the boot order is beyond access or the function is not supported by BIOS.  It is a great tool for use on older systems.

There are some effective tools to be used for booting from the relevant USB or CD flash drive. You need to use one of these ISO to USB tools or burn the downloaded ISO file.

PC CMOS cleaner will let you unlock the BIOS lock on your computer. It even recovers, decodes and displays the supervisor/user password in BIOS of any machine brand.

You will find the names of the most popular manufactures on the list mentioning the supported BIOSes and it is likely that your BIOS is enlisted.

This tool is actually a bootable CD for Linux OS. However, you don’t need to be concerned about OS compatibility.

After you launch the program, it will try to decode and display a list of passwords for a try.

If you run out of the list and still finds it impossible to unlock the BIOS, remove the password by using any of two options.

The second option will reset the BIOS settings to defaults, thereby requiring you to reconfigure it afterwards.

CMOSPwd by CGSecurity

CMOSPwd by CGSecurity

It is one of the most popular CMOS decryption tools in use since 2007.

The tool decodes the password safely stored in CMOS before displaying it. The tool supports a good number of BIOSes. You should check the list to know if yours is included or not. Learn how to stay secure online.

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!BIOS by Eleventh Alliance

BIOS by Eleventh Alliance

Yes, it is spelt correctly. The tool was developed to fight a brute attack on BIOS passwords. It allows you to restore the BIOS password.

It also has a Blaster option which is very powerful but dangerous. This is because, it has potentials to corrupt your BIOS completely.

How To Invalidate The CMOS Checksum Manually?

How To Invalidate The CMOS Checksum Manually

Yes, it is possible to do it manually if other tools such as CMOS De-Animation are not functioning or you cannot depend on the automated programs.

Use the debug.exe tool for BIOS password setup. It will invalidate the CMOS checksum in the same way as CMOS De-Animator.

Just type two commands into the debug tool to accomplish the task if your computer first boots up in FreeDos.

  • Use Rufus or UNerbootin to install FreeDOS on your system.
  • Download the debug.exe Save it in the root of USB flash drive.
  • Boot up your system with the USB flash drive. Enter the following commands:

  • Press Ctrl, Alt and Del simultaneously to restart your system. It is likely that ‘CMOS checksum error’ will flash on the screen. You can now have an easy access to CMOS setup without having to enter a password.

About Puja Chatterjee

Puja ChatterjeePuja Chatterjee is a technical writer with extensive knowledge about computers. She graduated from BIMS. Her expertise includes technology writing and client relationship management gained through over 12 years of experience. Follow Her at Linkedin.

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