Recently bought a refurbed Precision T3500 with a 1T HDD. Trying to add a 2nd WD HDD with files from the old computer. The T3500 doesn't recognize the Drive. I think I have to go into the set up & change some settings but don't want to without guidance. Lots of info about mounting a new HDD, can't find anything dealing with a used drive.Very frustrating, but I'm open to learning!

TIA