My computer arrived and started up right away. I had problems getting the computer to properly install and function after all the windows 10 updates.  The built in diagnostics did not reveal the cause of the problem.I contacted the seller, David, sent a replacement.  The new to me computer is running great.After having all windows 10 updates done I have now added a SSD drive to be the C: drive.  Boot up is fast and quite.Customer support is a key aspect to consider when purchasing refurbished computer systems.Thank you