"Checksum bad" error message

Occasionally when my computer is not being used but is on it shuts down and hangs up with a black and white screen which has, among other things, this:

ERROR
251: System Cmos checksum bad - Default Configuration used
ERROR
211: Keyboard Error

When it happens, nothing works except shutting it off with the power switch and restarting it. Sometimes the same message comes up on restart, but eventually, with enough attempts, it boots normally and functions alright for a while. What?

 

Hello hhanover,

The battery is failing: http://www.pcguide.com/ts/x/sys/booterrGBER08-c.html the specific reference.

http://www.pcguide.com/ts/x/sys/booterr-i.htm Boot error trouble shooting page.

The keyboard error I think is connected.

Regards - Charles