Three weeks after purchasing this renewed unit when trying to start received the following error message on my monitor "Error! Memory configured incorrectly. Please enter setup for memory information details. System halted!" Call TekRefurbs and spoke with Kim (customer service). She knew immediately a couple of things to try. She walked me through step by step on how to reseat the DIMM cards. I struggled a bit to remove the drive in order to get to the DIMM cards, but Kim was very patient the entire time and got me through the whole process. Unit is back up and performing well. Thanks Kim!!