@ArrBianca usually that means the internal battery that maintains configuration state went dead (the little CR2032 coin cell in desktops... not sure what laptops use)
You get "checksum invalid" because the memory holding that configuration resets to... whatever its uninitialised values are, which are basically junk values.
@ArrBianca I definitely don't know how they handle it on more modern laptops. Especially hermetically sealed ones like Apple, so I'm afraid I can't be of much use there :(
@ArrBianca ah yes, that would do it as well!
(I didn't know it was newwwww!)
@SomeEgrets my solution was to return the less than 12-hour old computer and get an exchange. Fixed the problem right away :p