|For a desktop computer, those errors can also be caused by the battery on the mboard being installed backwards in it's socket.|
If it's a desktop computer, the + should be showing on the side of the battery you can see when it's installed. If that's correct, replace the battery.
If it's a laptop, you will need to consult the Service manual for it for where it is, what it looks like, how to replace it.
If it's an IBM or Lenovo laptop.....
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