If the problem occurs after the computer is turned on, the CMOS battery may or may not already be defective. Leave the computer turned on for a few 2-3 weeks before replacing the CMOS battery. Sometimes, if you leave the computer on, the battery may charge normally.

On Windows, CMOS stands for Complementary Metal-Oxide Semiconductor. It’s actually the battery-backed memory found on all of your computer’s motherboards. The term also describes a storage technology that helps a particular BIOS (Basic Input/Output) system program storeThere are important system data such as date and time settings, hot shoe and boot sequence, disk information and most other high system configurations on your PC.

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How do I fix CMOS settings?

Look in the CMOS configuration for a package to reset CMOS values, which can be a default or an alternative to loading default security settings.
Atdisplay and select, you will get a response if you are sure you want to load the default values.
Once the Go Delinquent values ​​are set, be sure to return to Save and Exit.

If you have a similar memory issue, your computer will display a CMOS Checksum Bad error before starting Windows. In this report, we will show you the causes you see, the errors and how to fix them.

Which CMOS Causes Checksum Errors On Windows?

How do I fix the CMOS error on my computer?

Restart your computer. A normal reboot usually generates a new checksum and fixes the error.
Also download the BIOS update. Download the update from the motherboard manufacturer’s website.
Reset BIOS.
Replace certain types of CMOS batteries.
Contact a technician or computer repair technician.

“Checksum” describes a value (number or letter) used to control or verify the integrity of ring folders on a storage device. You will get your company’s CMOS Checksum Bad error on a PC if the CMOS memory values ​​are corrupted. This may be due to installing an incorrect or corrupted BIOS update. The CMOS itself is powered by a dedicated battery, so a CMOS checksum error can also occur when the main CMOS battery is low, bad, or old. Splashes

Incorrectly turning on or unplugging a new PC from the outlet can also result in a checksum error You are CMOS. Despite many causal factors, “CMOS checksum is usually wrong” is easy to fix.

Fun fact: cmoscoast.com is also sent as Real Time Clock (RTC), COS-MOS (Complementary Metal Oxide Semiconductor Symmetry) or Non-Volatile RAM (NVRAM).

How To Fix Bad CMOS Checksum Error

If your Windows PC is showing a big “Checksum cmos Bad” error during shutdown, the troubleshooting solutions below may fix the problem.

Perform automatic repair

You can also use Startup Repair to fix problems that prevent Windows from starting correctly. Turn off your home computer and follow the instructions below.

  1. When your computer is on, select > Settings and security updates > Advanced startup > Restart now.

If Windows won’t start, turn off your Ultimate computer and turn it back on. When the screen turns on, press the F8 or F11 key until the advanced boot menu appears on the screen.

Another The way to insert an extended boot menu is to restart your computer regularly. That is, turn on the computer and hold the power button until the computer turns off. Repeat this three times and your computer should load the advanced boot area on the third try.

  1. Select “Troubleshoot”.
  1. Select additional options.
  1. Select “Start Recovery”.
  1. Enter your account password and click Next. Leave the dialog blank, click next if your credit account is not password protected.

The tool will diagnose your PC and attempt to fix approach errors preventing it from fully booting. Once the process is complete, restart your computer and check if the CMOS checksum is fixed.

Reset BIOS to factory settings in store

Launching the BIOS will completely reset and delete all information stored in these CMOS. On the plus side, your current process also removes bad entries and invalid BIOS values. The way Customers land on your website and reset BIOS to factory settings, depends on your motherboard and PC brand.

See our Windows BIOS reset guide for more information. Be sure to restart your computer later by resetting your BIOS settings. This will restore the checksum standards and fix the CMOS error.

Press F1 or F2 on the World Wide Web error page to enter the BIOS setup program. At the top of this page, select Load Defaults, Load Set Defaults, or another option to restore BIOS defaults.

Some computer devices may require you to press another key (usually Del or F8) to access the Windows BIOS setup page. Check the instructions on each error page to make sure.

If customers leave the error page, they can completely reset their BIOS settings through the advanced Windows boot menu. Turn off your computer and wait about 20-30 seconds until it shuts down completely.

  1. Press and hold the power buttonpress F8 or F11 to start the computer just before the Windows logo appears on the screen.
  2. Select Troubleshoot.
  1. Select additional options.
  1. Select UEFI firmware settings.
  1. Click Restart to start the computer using the BIOS setup utility.

The BIOS setup interface varies depending on the make of your PC. However, you should find an alternative to resetting the BIOS in the appropriate section of the BIOS utility.

  1. Go to exit, press the down arrow to move the selector to successfully load default settings, and press enter.

How to reset CMOS settings on a laptop/desktop?

Here we present 6 best ways to reset CMOS to BIOS settings on laptop/desktop. Method 1: Reset BIOS settings to default values ​​using the factory reset option Method 2: Reset configuration data Method 3: Full CMOS reset Method 1: Reset BIOS settings to default using the factory reset option

If you can’t find a way to bypass the BIOS settings, please contact your PC manufacturer or refer to your device manual.

  1. Select Yes and press Enter.
  1. Move any cursor to Exit Saving Changes and press Enter.

This will reset your PC’s BIOS settings to default and shut down Windows. To make surethat a shutdown problem is imminent, turn off your computer and turn it back on. Try the following troubleshooting step if someone is still getting the CMOS Checksum Bad error when turning on the computer. BIOS

How to fix CMOS memory not responding?

But often we do not understand the root cause of the problem and therefore have no idea how we can help solve it. If this is happening so that you can use your computer or your friend’s computer, a possible solution is to reset the BIOS settings, and in order to do this, everyone needs to clear the CMOS memory.


The update should perform a BIOS change if your PC’s BIOS copy does not match the latest version on the manufacturer’s website (check all “Driver Download” or “BIOS”). Download any BIOS utilities that contain the update for your PC model, go home as an administrator and let each tool automatically update your device’s BIOS.

Before proceeding, please be aware that the BIOS is a sensitive component of the PC motherboard. Incorrect installation or updating of the BIOS can cause permanent damage to the motherboard. At the time of this writing, follow your PC manufacturer’s instructions to avoid damaging your favorite device.

However, we strongly recommend that you only download full BIOS files from your PC manufacturer’s website. Also make sure that the modification BIOS refers to your PC model. Installing the BIOS of another device on a home PC breaks the motherboard.

Can CMOS get corrupted?

CMOS corruption is a common favorite event. Unfortunately, in most cases this is due to a motherboard failure, but this is usually not a rule of thumb. The problem may be in the BIOS / UEFI, most likely the CMOS battery is faulty.

Lastly, do not shut down or restart your computer while updating the BIOS. Any malfunctions (such as power surges and power outages) during operation can damage the BIOS or motherboard.

Replace CMOS battery

As mentioned earlier, if the rear CMOS battery is dead, your computer will not be able to verify the integrity of the BIOS files. Signs of a bad CMOS battery include date and time, unresponsive peripherals, internet connection issues, and more.

If you’re still getting a CMOS checksum error after applying these fixes, the CMOS battery itself is probably bad. Or maybe it has been moved from its actual position.

Resetting the CMOS battery should only be done if you are an experienced computer technician. Otherwise, contact your local repair center or PC manufacturer.

Check for physical appearances Drives

Partial or complete damage to your PC motherboard can also cause an error like “Invalid CMOS Checksum”. Take your computer to a repair center to inspect the motherboard for damage.