CMOS Checksum Errors – Fix Them Right Away

Causes of CMOS checksum bad error are multiple. The following lists some of the most common reasons. Fortunately, though the situation looks dire, the solutions are actually pretty simple.


Common Causes


The following are the most frequently cited reasons for this error. The solutions are also provided. They are: the CMOS battery is not working properly or has expired; the computer was not shut down correctly; this happens when you shut off the main power without turning off the computer. The third culprit could be a virus.


CMOS Checksum Bad Error Solutions


You should figure out first which of the aforementioned problems is causing the error. Then you can try the solutions offered here.


Run an Antivirus Scanner


Scan your computer just to be safe. It’s rare that viruses will affect the CMOS this way, but it pays to be sure. If a virus is detected, let your scanner remove it. If the problem disappears, then the virus was the culprit. If the error message persists, you should try the following.


Malfunctioning Battery


If battery is the issue, you need to replace it. The first step is to reboot your computer just to check if the error is still there. If it is, go into the settings (refer to your computer manual). Write down all the settings. Store this in a safe place.



Find the battery and take it out. The battery is shaped like a coin. It is silver, shiny and flat. Get all the info about the battery. Refer to your computer manual if you can’t find it. Install a new battery. Enter the settings you wrote down. Turn your computer on. If this doesn’t work, then check the other causes of CMOS checksum bad error.


An Updated BIOS


An updated BIOS may have caused the system to reset. Get your computer manual and compare the settings. You can find the defaults in the user manual. Note that some viruses change these settings. If you did not make any updates, run a virus scanner.



Improper Computer Shutdown


If you turn off the main power supply before shutting down Windows first, this error message may appear. The easiest way to prevent this is by being certain the operating system has completely shut down.


If you updated the settings and your computer stops working, the update was probably incorrect. The only solution is to revert back to the older settings. Try to input the older values if possible.


What Does the Error Mean Anyway?


The checksum is a code designed to check the settings kept in the memory of the CMOSBoman Rustom Irani>. The error image appears when it releases values that are incorrect. The memory maintains a particular value to protect the BIOS program. Every time your computer boots up, this value is compared to the one kept in the memory. If the figures do not correspond, the error message will appear.


When studying the causes of CMOS checksum bad error, keep in mind that computers will react to it in different ways. Some computers will display the error message but continue to boot up. In this case it will use the new settings in the BIOS.


Other systems will stop booting and ask the user to restore the default settings. Regardless of how the computer reacts, it’s important that you perform the steps described above to rectify the problem.


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