When I Open My Pc The Message Appears On Screen "Cmos Checksum Error". What Does This Mean?

This issue is caused when the CMOS values are incorrect. This issue can occur because of any of the below possibilities.

Bad or old CMOS battery.
BIOS update.
Disconnecting power from computer without shutting down computer
                                    Solution:-
       Bad or old CMOS battery ---------

Attempt to reboot the computer. If error still occurs after rebooting the computer enter CMOS setup and check all values, this includes verifying the time and date are correct. Once everything has been verified and/or changed make sure you save and exit CMOS setup.

If you have a Phoenix BIOS and have an option for 'Reset Configuration Data', set this value to 'Yes' and save and exit the CMOS.

Note: If this issue continues to occur after you turn off your computer off it is possible that the CMOS battery may be failing or already bad. Before considering replacing the CMOS battery try leaving your computer on for several days. Additional information about replacing the CMOS battery can be found on document CH000239.

Computer improperly turned off

If the computer was had the power disconnected while it was still running it is possible this could cause the CMOS to become corrupt. Ensure that the computer is ready to be shut off before turning off the computer. If you have a laptop computer ensure that the battery is charged before disconnecting the power connection.

If the CMOS values have become corrupted entering the values in CMOS setup and saving and exiting CMOS should resolve your issues. Additional information about entering the BIOS setup can be found on document CH000192.