How to Clear and Reset CMOS or BIOS
When you are suffering an unkown BIOS password or a chaos BIOS setting, you may need to clear CMOS/BIOS settings. that will reset the BIOS to the initial status. Here I list some conditions that you may need to clear the BIOS, but you must not always should do it like that if your BIOS support to load default settings which I will introduce below.
If you only want to change BIOS password, please refer to: How to Set or Reset BIOS Password
1. What's the clear BIOS or CMOS?
Clear BIOS is often called clear CMOS, or discharging the BIOS battery. We know CMOS's status is always keeping by the battery. If you remove it, the CMOS's settings will be cleared.
When the computer is powered on again, the motherboard has to read the default settings from the BIOS chipset whichi is intergrated in the factory or upgraded by someone later. For most of us, it is the initial BIOS settings.
2. When we should/may clear BIOS?
A. If you forget the BIOS password or the boot password
Clear BIOS will initialize the BIOS status, the password will be removed surely.
B. Overclocking the CPU
When you find some errors occured in overclocking, and you don't be sure all the default settings which have been changed, you can clear the BIOS, all the settings changed will be reset.
C. Chaos settings in BIOS
When you confuse about the BIOS settings which have been changed, you can clear the BIOS at anytime, you can start from all over again.
For older BIOS, it is a common requirement for many older BIOS/computers. When the BIOS is upgraded, you many need to clear BIOS to complete upgrading.
If your computer has some subtle errors that you suspect. you can clear BIOS to confirm about them.
Some other reasons I don't think about, if you know, let me know freely, thanks.
3. How to clear BIOS/CMOS settings?
Note: For many newer BIOS, we do not need to open the shield and clear BIOS manually. you can load the default BIOS when you entered the BIOS interface. Just do it and save to CMOS, that will take the same effect as clear BIOS.
The method of clear BIOS is very simple. you should open the shield of the computer, and try to find the BIOS jumper. you may find three BIOS jumper pins around the battery. If you do not find it, you can look for help from your manual book of the computer/motherboard.
Some sample of the BIOS jumper:
If you find it. pull the BIOS jumper and plug it in other two pins for several seconds. and then recover. OK, that is all. Restart your computer.