The CMOS checksum error is a standard system error that happens in Windows computers. The error appears when you try to start your computer. An error message comes up that says, “CMOS Checksum Error – Defaults loaded.” The error is nothing but a result of conflict between Complementary Metal-Oxide Semiconductor (CMOS) and Basic Input/Output System (BIOS).

Sometimes the error displays the message: “Press F1 to continue, F2 to enter SETUP.” But if you press F1, the error doesn’t resolve. The error is highly troublesome, and you have to solve this error as soon as possible if you want to use your PC. And to help you with CMOS checksum error, we are going to discuss some useful solutions in this article. So, continue reading to find out more about the CMOS checksum error.

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What is causing CMOS checksum error:

Complimentary Metal-oxide Semiconductor or CMOS is a semiconductor chip on the motherboard of your computer. It is responsible for storing Information regarding BIOS. BIOS(Basic Input/Output System) does the job of initiating and testing the hardware, for example, the CPU, memory, keyboard, mouse, etc. The error happens when CMOS fails to check the data stored in BIOS, which is otherwise known as the Checksum check failure. The error can occur when CMOS runs out of battery, or the BIOS data is corrupted. Also, when malfunction happens in the BIOS, the viruses can change the value of BIOS data which will lead to the Checksum check failure. CMOS is a part of the motherboard. So, if in any way the motherboard of your computer is damaged, that can cause the CMOS Checksum error. You learned all the reasons behind the CMOS Checksum error and now let’s discuss the solutions.

Solutions to Fix the CMOS Checksum Error:

Solution 1: Follow the traditional way

Sometimes when you shut down your computer directly from the power button without following the traditional steps of shutting down a computer, it disrupts your computer. That’s why the CMOS Checksum error welcomes you the next time you start your computer. In this scenario, you only have to follow the on-screen instructions. Hopefully, the error gets solved, and you restart your computer successfully.

Solution 2: Check and replace the CMOS battery

CMOS uses a battery to store power after you shut down your computer. Generally, the CMOS battery gets faulty after 5years. If you are encountering the CMOS Checksum error on an old computer, then you should check the battery. Carefully open the computer case and remove the old battery. If you are thinking you won’t be able to do it properly, then contact a computer technician.

Solution 3: Check the terminals of CMOS battery

Even after replacing the CMOS battery, you are facing the error, and then the problem is with the battery terminals. To fix this problem, follow these steps.

  • The CMOS battery needs more than three terminals to work efficiently.
  • Carefully remove the CMOS battery from the computer, then check the terminals.
  • You have to bend the positive pin in and negative pin-up.
  • Once again, fit the battery in the battery socket properly.
  • Put everything back together and restart your compute.  Now see the error appears again.

Solution 4: Reset the BIOS

In some cases, the CMOS Checksum error can arise as a result of malware infection. The malware infection can interrupt BIOS functionality. In this situation Resetting your BIOS can solve the CMOS Checksum error. To reset the BIOS, follow the steps given below.

  • When you see the error message “Press F1 to continue, F2 to enter SETUP”, you have to press F2.
  • The BIOS settings window will open.
  • You can see the key used on your computer screen.
  • You have to choose the Load Defaults.
  • If your display shows Load BIOS Defaults(Y/N), press “Y“.
  • Leave the BIOS settings window and restart your computer.
  • If you see the error again, enter the BIOS settings window following the previous steps.
  • This time you select the Standard CMOS Features.
  • Here, you have to correct the Date and Time.
  • Click on the SATA or Drive
  • If your computer has no diskette drives, choose Disable/None/Not Detected to disable the diskette drive scanning.
  • You must save the changes before you leaving the BIOS settings window.
  • Now, try restarting your computer.

Solution 5: Fix the error by updating BIOS

BIOS is essential for your computer to startup. If the BIOS is showing problems like the CMOS Checksum error, then you should check for BIOS updates. However, manually updating BIOS can be harmful to your computer. So, it would be best if you tried it under the guidance of a technician. Follow these steps given below to update your BIOS.

  • Press Windows key +R.
  • Type “msinfo32” and press OK.
  • Choose the System Information option.
  • Here, you can see the BIOS Version/Date installed on your computer.
  • Then, you have to go to the computer manufacturer’s website to see if your computer has the latest version of BIOS.
  • Here, you can download the available updates and install it on your computer.

Solution 6: Faulty Motherboard

If none of the above-mentioned solutions worked for you, then it indicates that your computer’s motherboard is at fault. If the motherboard somehow becomes damaged, that can cause the CMOS Checksum error. And you can’t do much to fix the motherboard on your own. So, you have no option except handing over your computer to a professional technician who will help you with replacing the motherboard.

CMOS Checksum error is a very frustrating error for Windows users. CMOS is a delicate technology that often shows errors while booting your computer. In case, you aren’t able to start your PC, then CMOS is responsible for this. You need to fix this issue as quick as possible to use your computer productively.

We have provided some easy steps for you to fix the error. If the CMOS Checksum error is troubling your computer, you can use the solutions given above to resolve the error. We hope this guide was insightful. If you have any queries or feedback, please write down the comment in the below comment box.