What is CMOS checksum error?

Answer 1

CMOS checksum errors

Explanation: A checksum is computed as an error-detecting code, to protect the BIOS settings stored in the CMOS memory. Each time the system is booted this number is recomputed and checked against the stored value. If they do not match, an error message is generated to tell you that the CMOS memory contents may have been corrupted and therefore some settings may be wrong. BIOSes react in different ways to encountering this sort of error. Some will warn the user and then continue on with whatever settings were in the CMOS. Others will assume that the settings that were in the CMOS were corrupted and will load default values stored in the BIOS chip "for safety reasons". The error message will indicate which your system is doing.

Diagnosis: The most common cause of checksum errors in CMOS is a battery that is losing power. Viruses can also affect CMOS settings, and motherboard problems can also affect the stored values.

Recommendation: Follow the instructions in this section to address the CMOS corruption. You should make sure that all of the BIOS settings in the system are correct, by rebooting the system, going into BIOS setup and double-checking all the values (hopefully against a recent BIOS settings backup).
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Answer 2

On a standard PC motherboard, CMOS is used to hold data that is accessed by BIOS Setup. The CMOS memory is maintained when the system is off by a battery backup.

This error and possible causes with solutions, can be read here:

http://www.computerhope.com/issues/ch000237.htm

Good Luck

Answer 3

Stupid, you dont need a LONG explanation to sound smart, lol, cmos checksum error, means your cmos settings have been reset, if you have recently added/removed/or changed your hardware, than
dont worry about it, if not, than just open your computer case, look for the battery, go to a local store buy a new one, and insert, Voila! Fixed!

Answer 4

your cmos battery needs replacing