For the beginning we can say this is not an error it’s just an Warning that something happened with your CMOS battery, maybe it run out of power maybe it’s a new one and computer doesn’t recognize it.
To fix this warning try below methods:
Method 1 Reset CMOS settings in BIOS
When the warning appears press Del key to enter BIOS
Choose Load optimized default BIOS settings
Save and exit the BIOS.
The system will restart and it should recognize CPU at proper speed.
Method 2 Reset CMOS settings by removing Battery
To be safe, do this :
Take of all power cables
Remove the CMOS battery
Press the power button (so that any left current dies)
Then, move the jumpers one place, leave it for a second or two, and put them back to the original place
Put back CMOS battery.
[quote_box_center]If none of the above methods work, or it the warning appears later, then you may need a new motherboard battery.[/quote_box_center]