When you switch out the battery on the motherboard, you have to reset the date in the bios. To enter the bios, restart the computer, when the screen appears, hold down the F-2 key. You should see the words “Entering Setup” The next screen you should see would be the infamous bios. To Change the date follow the instructions on the bottom of the screen which normally is a plus or Minus, use the arrow key to change the date. When you are through, you will want to save. Press the F10 key, than press enter.