Many average computer users will find a time when they need to remove the CMOS battery to reset the BIOS on their computer. There can be many reasons why you might want to remove the CMOS battery.
Sometimes when you buy a second-hand computer from an auction or government department, it has a password that stops you from changing settings in the bios. I can’t tell you how annoying this is. I have tried numerous ways to get rid of this password. Here are some things I have tried.
Please read an article on How to open a computer case safely…
Remove the CMOS Battery
If you remove this battery, all CMOS information (including the BIOS password) will be lost.
- Shutdown your computer and remove all power and plugs.
- Open your computer case. Here are some safety tips.
- Carefully remove the CMOS battery for 20 minutes, then replace it. (Sometimes longer)
- Plug in your computer and start it. Go into the bios by pressing F2, F10 or maybe the delete key. This must be pressed quickly and at the right time or you will have to reboot an try again.
- Find the restore factory settings option and choose this.
- Then save and exit.
Sometimes this will not work as some manufacturers backup the power to the CMOS chipset by using a capacitor. How annoying.. You can try taking the battery out and leaving it over night. That has worked for me before. (Sometimes days)
Reset the bios by moving the jumper pin settings
On older computers, to fully reset the BIOS, you need to move a small jumper that is located on your motherboard. It is a little plastic cover going over some pins on your motherboard.
If you have your motherboard manual it will tell you how to reset your bios by moving the jumper pins. They could be called BIOS, CLEAR, CLEAR CMOS, CLR, CLRPWD, PASSWD, PASSWORD, PWD.
It is usually done by moving the jumper located near the battery, from the first and second pin to the second and third. Here’s how:
- Shut down your computer.
- Touch the inside metal casing of your computer and move the jumpers from pin 1 and 2 to 2 and 3.
- Press the power button or on off button on your computer.
- Replace the jumper where you found it and restart your computer.
- Go into your BIOS and restore default settings or factory settings.
Sometimes you can remove a jumper completely and restart your computer, and the password will be gone.
Here is an example:
I bought a HP D530 Small form desktop and its boot sequence had been changed to only boot from a network. When I went to change the Bios settings it had a Password to enter the bios.. After 3 wrong passwords it would let me into the BIOS, but would not let me change anything.. On the motherboard next to the Cmos battery there was two pins with a jumper on them named PASS. I removed this jumper completely and restarted the computer. The password was gone. I went straight in and found the option to restore default settings. I shut down again and replaced the jumper. All done…
I have come across some other motherboards that did not even have any jumper pins for the bios. However after leaving the battery out for a few days, everything was fine..
Depending on what bios version your computer has, there is probably a password out there to get you in. I avoid dealing with these passwords as there are so many now. There are about 40 Award bios backdoor passwords alone. Some examples are: AWARD SW, BIOSTAR, _award, aLLY, CONDO, and so on.. Some examples for AMI Bios are: AMI, PASSWORD, CONDO, AMI_SW, etc. If you want more information google your Bios.
- When working with the motherboard it is recommended that you have an anti static strap to release the static electricity build up from your body. How to open a computer case safely…
- If you are not sure what you are doing, get a professional to do it.