What a CMOS password does and why you might need to remove it
A CMOS password is a security setting stored on a small battery-powered chip inside your computer that locks you out of the BIOS — the firmware that runs before your operating system loads. Unlike a Windows or Mac password, which you can reset through your user account, a CMOS password blocks access to the machine's deepest settings before any operating system even starts.
You might need to remove it if you inherited a computer from someone else, forgot the password yourself, or bought a used machine where the previous owner left it locked. The password protects against someone physically opening your computer and changing boot order or hardware settings, so removing it requires physical access to the machine's internals.
The method depends on your computer's manufacturer and age. Newer machines often have a firmware reset option in the BIOS itself. Older machines require you to physically locate and remove a jumper or battery. Both approaches take 15 minutes to an hour.
Key Takeaways
- A CMOS password locks the BIOS before Windows or Mac loads, and you cannot reset it through your operating system.
- Removing it requires opening your computer's case and either moving a jumper, removing a battery, or using a BIOS reset option if your machine has one.
- The exact method varies by manufacturer — Dell, HP, Lenovo, and custom-built machines each have different procedures.
- If you do not feel comfortable opening your computer, a local repair shop can do this in under an hour for a modest fee.
- After removal, you will need to reset the date and time in BIOS, since the CMOS battery powers the clock as well.
Finding your computer's manufacturer and model number
Before you open the case, you need to know what you are working with. The method for a Dell is different from the method for an HP or a custom-built machine. Write down your manufacturer and model number — you will need both to find the exact jumper location or reset procedure.
On a desktop, look at the case itself for a label. On a laptop, check the bottom panel or the inside of the battery compartment. If the machine is already powered off and you cannot see a label, search your computer's documentation or the manufacturer's website using the serial number, which is usually printed on a sticker near the power connector.
The jumper method for older desktops
Most desktop computers built before 2015 use a jumper — a small plastic cap that slides over two metal pins on the motherboard. Moving this jumper to a different pair of pins, or removing it entirely for 10 to 15 seconds, clears the CMOS password. This is the fastest method if you can locate the jumper.
Power off the computer completely, unplug it from the wall, and wait 30 seconds. Open the case by removing the side panel — usually held by two or three thumbscrews or clips. Look for a small plastic cap on the motherboard labeled PSWD, CLR_CMOS, CLEAR CMOS, or similar. The label is often printed directly on the motherboard next to the jumper. Move the cap to the adjacent pair of pins for 10 seconds, then move it back to its original position. Close the case, plug in the power, and restart.
If you cannot find the jumper or the label, consult your motherboard's manual — search the manufacturer's website using the model number printed on the motherboard itself. Some manufacturers place the jumper in different locations depending on the board revision.
The battery method for desktops and some laptops
If there is no jumper, or if moving it does not work, the next step is to remove the CMOS battery — a coin-shaped battery about the size of a dime that powers the BIOS settings and the system clock. Removing it for a few minutes drains the stored password.
Power off and unplug the computer. Open the case and locate the battery on the motherboard — it sits in a small circular holder and is usually labeled CR2032 or similar. Gently pry it out using a plastic spoon or a non-metal tool. Do not use a metal screwdriver, which can short the motherboard. Wait 10 to 15 minutes, then press it back into place. Close the case, plug in the power, and restart.
On some laptops, the battery is harder to reach and may require removing the keyboard or the entire bottom panel. If you are not comfortable disassembling a laptop, a repair shop is a safer choice — laptop internals are fragile and straightforward to damage.
BIOS reset options on newer machines
Computers made after 2015, especially business models from Dell, HP, and Lenovo, often have a built-in BIOS reset option. If you can reach the BIOS setup screen — usually by pressing Delete, F2, or F10 during startup — you may see a "Reset to Factory Defaults" or "Clear Security Settings" option. This erases the password without opening the case.
Restart the computer and watch the screen during the first few seconds. You will see a prompt like "Press F2 to enter Setup" or "Press Delete for BIOS Settings." Press the correct key and look for a menu option to reset or clear settings. The exact wording and location vary by manufacturer, so check your computer's manual or the manufacturer's website if you cannot find it.
Some newer machines require a service tag or service password to reset the BIOS, which only the original owner or the manufacturer can provide. If you own the machine and have proof of purchase, contact the manufacturer's support line with your serial number — they can sometimes provide the service password or walk you through a reset.
What to do after the password is removed
Once you restart the computer after removing the password, the BIOS will likely show an error message about the date and time being incorrect. This is normal — the CMOS battery also powers the system clock, and removing it resets the date to a factory default, usually January 1, 2000 or similar.
Enter the BIOS setup again using the same key you pressed before (Delete, F2, or F10). Look for a "System Time" or "Date and Time" option and set it to the current date and time. Save and exit. The computer will now boot normally, and you can set a new BIOS password if you want one, or leave it unprotected.
If the computer still will not boot after you have removed the password, restart it again and check the BIOS to make sure the boot order is set correctly — usually the hard drive or SSD should be first in the boot sequence. If you changed anything else while inside the case, undo those changes and try again.
When to take the computer to a repair shop
If you are not comfortable opening your computer, or if you have tried the jumper and battery methods without success, a local computer repair shop can remove the password in under an hour. Bring the computer and proof of ownership. The cost is usually between $50 and $150, depending on how much disassembly is required.
Some manufacturers also offer password removal services if you can prove you own the machine. Contact their support line with your serial number and ask about your options. Response time is usually longer than a local shop, but the cost may be lower or covered under warranty.
Frequently Asked Questions
Will removing the CMOS password erase my files or operating system?
No. The CMOS password is stored separately from your files and your operating system. Removing it only clears the BIOS settings. Your Windows, Mac, or Linux installation and all your data remain untouched. You will still need your operating system password to log in after the computer boots.
Can I remove a CMOS password without opening the computer?
Only if your computer has a BIOS reset option in the setup menu itself, which is common on newer business machines but rare on consumer models. If you cannot find this option, you will need to open the case to access the jumper or battery. If you are uncomfortable doing this, a repair shop can handle it.
What if I move the jumper and the password is still there?
Some motherboards have multiple jumper sets, and you may have moved the wrong one. Check your motherboard's manual to confirm you moved the PSWD or CLR_CMOS jumper specifically. If you cannot find the manual, try the battery method instead — it works on almost all machines.
How do I prevent someone from setting a CMOS password on my computer in the future?
Set a BIOS password yourself and keep it somewhere safe. You can also disable the BIOS setup option entirely in some machines, which prevents anyone from entering the BIOS without a password. Check your BIOS menu for a "Setup Lock" or "BIOS Lock" option. If you forget this password, you will face the same removal process.
Is it legal to remove a CMOS password from a computer I own?
Yes, if you own the computer or have the owner's permission. If you are removing it from a computer that belongs to someone else or to an employer, you may be breaking the law. Only remove a CMOS password from machines you own or have explicit permission to modify.