How to Clear CMOS?
The computer stores low-level settings like the system time and hardware setting in its CMOS. These settings are configured in the BIOS setup menu. Clearing the CMOS resets your BIOS back to their factory settings default state. In most of the cases, you can clear the CMOS from within the BIOS menu. In some cases you need to open your CPU’s cabinet and do it manually on your motherboard. Let’s discuss both the ways in detail, so that you can properly troubleshoot the problem of your computer yourself.
Use the BIOS Menu
The most convenient way to clear the CMOS is from your computer’s BIOS setup menu. To access the setup menu, you need to restart your computer and press the key that appears on your screen to let you go into the BIOS settings of your computer, mostly it’s the F2 key which allows you to enter into the BIOS settings of your computer. But, you need to see if its different for your computer.
Within the BIOS you need to find the Reset Option. It may be named Reset to Default, Load Factory Defaults, Clear BIOS settings, Load Setup Defaults, or something similar to this.
Select it with your arrow keys (←→), press Enter, and confirm the operation. Your BIOS will now use its default settings — if you have changed any BIOS settings in the past, you will have to change them again.
USE the CLEAR CMOS Motherboard Jumper
A lot of motherboards contain a jumper that can be used to clear the CMOS settings if your BIOS is not accessible. This is especially useful if the BIOS is password protected and you don’t have access to the password.
The exact location of the jumper can be found in the motherboard or your computer’s instruction manual. You should consult the manual for more detailed information if you want to use the motherboard jumper to clear CMOS.
Nevertheless, the fundamental procedure is quite similar on all computers. Flip the computer’s power switch to off to ensure it’s not receiving any power. Open the computer’s case and locate the jumper named something like CLR CMOS, CLEAR CMOS, CLEAR, PASSWORD, or CLR PWD – it will often be near the CMOS battery mentioned below. Before doing so make double sure you’re grounded so you don’t damage your motherboard with static electricity before touching it. Set the jumper to “clear” position, turn on your computer, turn it off again, set the jumper to its original position i.e., ON – and you are done.
Reseat the CMOS Battery
If your motherboard does not have a CLEAR CMOS jumper, you can often clear the CMOS settings by taking out the CMOS battery and replacing it in its slot. The CMOS battery provides power used to save the BIOS settings – this is how your computer keeps record of the time and date you see in the right hand side of the task bar in your window, it keeps working even when your computer has been powered off for a while – so removing the battery will remove the source of power and clear the settings. You need to reset the time and date of your computer once you replace the CMOS battery.
First of all, make sure that the computer is powered off and you are properly grounded so you won’t damage the motherboard with static electricity. Locate the round, flat, silver battery on the motherboard and carefully remove it. Wait for five minutes before reseating the battery.
Clearing the CMOS should always be done for a reason – such as troubleshooting a computer problem or sorting out a forgotten BIOS password. There’s no other reason to clear you CMOS if everything is working perfectly in order.