How to fix CMOS checksum error: Windows, battery, solutions

How to fix CMOS checksum error: Windows, battery, solutions

When a CMOS checksum error occurs during system startup, it could mean that the system has been restored to default factory settings. The CMOS contains data related to BIOS and may have been reinitialized, causing this error. This tutorial will walk you through how to get rid of this error.

What is checksum?

A checksum is an algorithm that is used in various programs, especially downloaded ones, to ensure the integrity of a file. 

What causes the CMOS checksum error?

The CMOS (Complementary Metal Oxide Semiconductor) checksum error appears when the information on the CMOS is corrupt. BIOS (Basic Input Output System) boots up your computer and also contains many settings for your PC's hardware, such as system time, boot priorities, speeds, etc. These settings are saved on the hard drive on CMOS. When you make changes to the BIOS settings, these events are saved to the CMOS and it ensures that everything will work fine the next time you boot your computer. CMOS is powered independently and always stays on even when your computer is off. And the most common cause of the checksum error is when the CMOS battery is dead. Without this battery, the CMOS can't store information, and BIOS can't read it. And this is why the checksum error happens. Among other reasons for the checksum error, there is a loss of power caused by a power surge or if the BIOS is damaged or corrupted. Fortunately, there are several ways to fix the CMOS checksum Error.

How do I fix the CMOS checksum error?

  • The first is by restarting your computer. This should create a new checksum and remove the error.

  • Download and launch BIOS update from the motherboard manufacturer's website. 

  • Another is by reinitializing the BIOS. Certain motherboards allow you to reset the BIOS settings directly with a switch. If not, simply removing the battery will cause a power loss to the motherboard, and the CMOS will reset.
  • The second is by changing the BIOS battery. The CMOS battery is a small pin found on the motherboard. You can either refer to the manual provided with your motherboard to change it or have a computer technician change it for you. If you'd like to try to do it yourself, refer to our article on the subject.

  • Check if your computer supports the correct date and time. Incorrect settings can interfere with updates. If the error persists, you can try the other options. 

  • You have completed all the steps above, but it still doesn't work? Then try installing and performing the upgrade with the media creation tool. You can download it from Windows 10 upgrade and download the site. If this hasn't fixed the issue, consult a technician to see if there was hardware damage that caused the problem.
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