If you want to learn the causes of CMOS checksum errors, it’s important to know what the CMOS checksum actually is. It is a code used to errors and make sure the BOS settings in the CMOS memory are safe. Simply put, the error message appears if the values returned are wrong.
Why the Errors Take Place
There are three possible reasons why this error will happen. The first is that the CMOs may not be working. It may be that the battery has expired or a virus or malware has altered its settings. Another possible reason why this happened is that the computer did not shut down correctly.
For instance, the machine may have been shut down without the computer being turned off. Computers running on Microsoft Windows require your system to be turned off prior to shutting down the main power.

How to Fix CMOS Problems
There are many possible solutions, one of them being to fix or replace the battery. Before you take out the battery, try rebooting the computer to see if the problem disappears. If it happens again, go to the CMOS and write down the settings. Now all you have to do is find the CMOs battery. Refer to your computer manual on how to take out the battery.
If you haven’t seen the device before, it is shaped like a coin and silver in color. Note down the size, volt and so on. Take out the old battery and put in a new one. Turn your computer on and check if that fixes the problem.
Updated BIOS
Another problem could be that the BIOS settings were changed or updated. Check your computer manual for the BIOS settings and compare it with the one on your computer. If the settings have been changed, restore them according to the values in your manual. If the settings have been changed by a virus then you probably won’t be able to restore it. The best way to deal with it is to use an antivirus scanner.
Improper Shutdown
As stated earlier the problem will appear if the computer was not shut down correctly. If this happens the CMOS settings will be corrupted, leading to the error message. You can avoid this from happening by shutting down Windows properly. Click Start and choose Shut Down Computer. Wait for it to shut down completely before turning off the main power.
Other Facts about CMOS
What is CMOS?
It is a complementary metal oxide semiconductor that is integrated into personal computers. It is used to hold basic data such as the system configuration settings, time and date required by the basic input/output system (BIOS). The CMOS is found not just in computers but in other electronic devices like digital cameras.
The CMOS has a lot of functions including Power On Self Test (POST). When you boot up a computer, the power supply goes up. The CMOS will then perform several tests to make sure that all the computer’s components are working fine. One of the components that it checks is the RAM. Some users actually disable the RAM check because it slows loading time.
Unless you know the causes of CMOS checksum errors, the problem may seem intimidating. But the facts outlined above should help you resolve the problem in case it comes up again.
Den is a free lancer writer and content builder of http://www.iqio.org/ and now a days he is doing work on CMOS Checksum Errors.
