when booting, my system shows this: "CMOS checksum error-default loaded Press F1 to continue." this started early last year but i have not bn able to do anything concerning this. maybe because after pressing F1, it loads and i can work (though, it has stopped remembering dates and time). cud it be doing some underground damage to my system unknown to me? because recently my system has failed on few occasions to boot completely thereby prompting me to boot in safe mood with minimal capabilities. after doing this , i normally shut down and start all over before it starts "working well" again.

Could it be the CMOS battery? And if Yes, can i change it? How much does this go for? Thanks for your anticipated responses.

Yes, it's the CMOS battery. I have no idea about the cost, but you can probably get it at the famous computer village.

The CMOS battery is weak. A new one costs about N800, I think.

CMOS checksum error 99% of the time means your battery is dead, and needs to be replaced. The other 1% means that there could be other underlying issues such has hardware failure. Since you said you could continue booting then it's probably just the battery. It isn't doing any damage to your computer but it is rather annoying, slowing up the boot process. If you have your BIOS settings for auto detect then you should be fine, but problems may arise if you try to upgrade your computer without replacing the battery, because settings may need to be made in the bios to accommodate the new hardware.

CMOS batteries are easy to come by I just hope you have a newer motherboard that uses the coin cell battery( watch battery) and not the barrel type solder battery which is connected to the motherboard. Open up the computer and take a look see on the motherboard, but try not to touch anything.