top of page


Jefferson Rodrigues
Jefferson Rodrigues


How to Download and Use KILLCMOS to Reset BIOS Password

If you have forgotten your BIOS password and cannot access your computer, you may need to use a tool called KILLCMOS to reset it. KILLCMOS is a small program that can clear the CMOS RAM, which stores the BIOS settings and password. By clearing the CMOS RAM, you can restore the BIOS settings to default and remove the password. However, KILLCMOS only works on older BIOS versions and may not be compatible with newer ones. In this article, we will show you how to download and use KILLCMOS to reset your BIOS password.


Step 1: Download KILLCMOS and FreeDOS

KILLCMOS is a DOS-based program, which means you need to boot your computer from a DOS environment to run it. You can use a USB flash drive or a CD/DVD to create a bootable DOS disk. One of the easiest ways to do this is to use FreeDOS, a free and open source operating system that mimics DOS. You can download KILLCMOS from [this link] and FreeDOS from [this link]. You will also need a tool called Rufus to create the bootable disk. You can download Rufus from [this link].

Step 2: Create a Bootable DOS Disk with Rufus

After downloading the files, you need to create a bootable DOS disk with Rufus. Follow these steps:

  • Insert your USB flash drive or CD/DVD into your computer.

  • Open Rufus and select your device under "Device".

  • Select "FreeDOS" under "Boot selection".

  • Click on "START" and wait for Rufus to format your device and copy the FreeDOS files.

  • When Rufus is done, close it and open your device in File Explorer.

  • Copy the KILLCMOS file ( to your device.

  • Eject your device safely from your computer.

Step 3: Boot Your Computer from the DOS Disk

Now you need to boot your computer from the DOS disk you created. Follow these steps:

  • Insert your device into the computer you want to reset the BIOS password.

  • Restart your computer and press the key that opens the boot menu. This key may vary depending on your computer model, but it is usually F12, F10, F9, F8, or Esc.

  • Select your device from the boot menu and press Enter.

  • Your computer should boot into FreeDOS. You will see a command prompt that says "C:\>".

Step 4: Run KILLCMOS and Reset Your BIOS Password

The final step is to run KILLCMOS and reset your BIOS password. Follow these steps:

  • Type "" at the command prompt and press Enter.

  • The program will ask you if you want to unzip it. Type "Y" and press Enter.

  • The program will unzip itself and create a folder called "killcmos". Type "cd killcmos" and press Enter.

  • Type "killcmos.exe" and press Enter.

  • The program will warn you that it will erase all CMOS settings. Type "Y" and press Enter.

  • The program will run for a few seconds and then display a message that says "CMOS checksum invalid - defaults loaded". This means that the CMOS RAM has been cleared and the BIOS settings have been restored to default.

  • Press any key to reboot your computer.

Congratulations! You have successfully reset your BIOS password using KILLCMOS. You should now be able to access your computer without entering a password. However, you may need to adjust some BIOS settings according to your preferences, such as the boot order, the date and time, etc. You can do this by pressing the key that opens the BIOS setup, which is usually F2, F1, Del, or Esc.


This article is for informational purposes only. We are not responsible for any damage or data loss that may occur as a result of following this guide. Use KILLCMOS at your own risk. KILLCMOS may not work on some BIOS versions and may cause your computer to malfunction. Always backup your important data before attempting to reset your BIOS password.




  • bucher bestseller
    bucher bestseller
  • Jefferson Rodrigues
    Jefferson Rodrigues
  • Лучший Выбор Администрации
    Лучший Выбор Администрации
bottom of page