Please open up Darkroom and go to GLOBAL SETTINGS in the top right-hand corner and then hit PRINTER OPTIONS to the left and then ADD PRINTER, which is back over to the top right and then (hit the printer that is high lighted blue in the pic attached) and then hit ADD PRINTER towards the bottom of that box. That is a way to get the computer to recognize the printer. And, of course, make sure the printer is plugged into the side of the Mini PC where it is labeled "Printer"