When I plug in the power cord, it automatically boots up with a message"The CMOS checksum is invalid

[LarryHawaii]

After I get that message, it boots up normally.  I was told this may indicate a mother board going bad although the computer is only two years old.

[itsmyname]

There is a small battery, about the size of a $0.25 coin, on the motherboard.

The battery gives a "trickle" of power to the CMOS, to maintain the values stored in the CMOS.

When the battery dies, the values in the CMOS are lost, and you get that error-message.

Remove the battery from its socket, and read the etched part-number on its surface.

Spend a dollar or two to buy a replacement battery.

Insert it.

Power-on your computer.

Enter BIOS SETUP.

Set the date/time.

Save/Exit from SETUP.

[TheOldMan]

Along with the info from @itsmyname , you might need to set the BIOS to defaults values, there is a setting for "defaults" while you are in there setting the date/time.

The typical CMOS battery is a CR2032