CMOS checksum error on Windows/ How to fix?

CMOS checksum error happens during system startup, the issue is between the CMOS and the Bios. After you switch off your computer, CMOS keeps record of the number that can blend with another that the BIOS produce during Startup. So if the number the two Value generates did not match it leads to checksum error.

CMOS checksum error

Causes Of CMOS checksum

  • Corrupted or Outdated Bios- when the Bios is out of date it is no longer sync with the operating system and other hardware thereby causing an error
  • Dead battery –  when your PC battery dies for some time the Bios will not be able to bring back the correct checksum value and your PC will now use the Bios default settings which leads to error
  • When your PC Is badly shutdown

Ways To Fix CMOS checksum error

These are possible solutions to these errors, all you need is to try each solution Provided below to solve the issue.

Try To Restart your PC

All you need is to follow the computer instructionsand restart your computer When it’s done booting. 

Reset your Bios

  • Pres the Power button and then Tap on the “F 10 ” Key, for HP, Click on “F2” Key
  • Setup and Boot Options appears on the screen for you to select
  • Clickon “Setup” tab
  • Tap on “F9” button to reset it.
  • Press on “Yes” tab to confirm.  In some computers you see things like, “restore Security Settings to Factory settings” beneathSecurity widget. Click on “F10” Key to save

Upgrade Bios

Try to update Bios but before you do that, below are basic thing you need to know

  • Ensure you update from your PC manufacturer
  • Do not shutdown or reboot the computer until you are instructed to do so
  • Ensure the AC adapter is connected
  • Make sure you update with the current Bios version
  • Scan your computer for virus

Replace The Battery

This is a small battery on the motherboard that gives power to the CMOS when you turn off the computer power supply.  The battery makes sure the Bios loads the accurate settings to enable PC start up normally.  So you can replace the battery.

Repair the Battery terminals

When the battery has more the three volts the CMOS works without having issue and also brings back the correct Bios settings.  Thus, it could be a power issue and not the batter itself . The positive and negative pins that attract power from the battery may be badly connected thereby not supplying power

  • Firstly, remove the battery
  • Bend the negative pin upward and then bend the positive pin in
  • Replace the battery and then see if the issue is fixed.


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