How to clear an unknown BIOS or CMOS password

Updated 8/2/2020

Sometimes users are faced with a password prompt upon boot or the BIOS or CMOS configuration is locked as shown in the image below. If you don’t know the BIOS password, you need to clear it. The following sections provide instructions on how to do this using different methods.

Delete with a jumper (recommended)

Follow these steps to clear BIOS or CMOS password using a hardware jumper.

attention

If you work inside a computer, make sure you are aware of the potential damage ESD can cause.

On the computer’s motherboard, locate the BIOS or password override jumper or DIP switch and change its position. This jumper is often called CLEAR, CLEAR CMOS, JCMOS1, CLR, CLRPWD, PASSWD, PASSWORD, PSWD, or PWD. To clear, remove the jumper from the two currently covered pins and place it over the remaining two jumpers. An example of the different jumper positions is shown in the picture. Some computers can also clear the password by keeping the jumper open (one or no pin covered).

What if I can’t find the CMOS password jumper?

The following list shows the general locations of the CMOS jumpers. It’s important to realize that most motherboards have several different jumpers, so you need to make sure you’re changing the correct jumper. If you cannot find the password jumper, check your motherboard documentation by reading the manual or downloading it from the manufacturer’s website.

On the edge of the motherboard – Most of the jumpers are located on the side of the motherboard for easy access. Check by looking at all visible edges of the motherboard.

By CMOS battery – Some manufacturers place the jumper to clear the CMOS or BIOS password through the CMOS battery itself.

through the transformer – Some manufacturers place the jumpers next to the computer’s CPU.

Under laptop keyboard or base – On a laptop computer, the DIP switches are located under the keyboard or on the bottom of the computer. It is usually located in a compartment like the one that contains the memory. (Laptops typically use DIP switches, not jumpers).

Once the appropriate jumper or DIP switch has been found and toggled, the password should be cleared. Turn on your device to verify that the password has been reset. After the password is cleared, turn off the computer and return the jumper or DIP switch to its original position.

Lever the CMOS stack

Removing the CMOS battery as shown in the photo will cause the system to lose all CMOS settings including the BIOS password. Locate and remove the CMOS battery from the motherboard for at least five minutes, then reinsert the battery and turn the computer back on.

Generic Passwords

Try using generic CMOS passwords. It should be noted that many of these default passwords are for older motherboards and will no longer work with newer computers.

Skip the CMOS solder balls

Older computers, especially older laptops, don’t have jumpers or DIP switches. They require the user to pop a pair of solder balls onto a circuit board. The identification and location of these solder bumps can vary, and if they are not included in the computer documentation, they can only be obtained from the computer manufacturer.

Once you’ve identified the solder bumps, you can pop them by placing a flathead screwdriver across the two bumps and leaving it on those bumps while you turn on the computer. Once the computer boots up, turn it off and remove the screwdriver.

Contact the manufacturer

If none of the previous sections solved your problem, we recommend that you contact the computer or motherboard manufacturer to learn how to delete the computer password.