8600 printer won't print. Only shows preparing printer on the screen. I have never used this. It's a refurbished machine.

Apparently not well refurbished. HP printers are pretty good about bugging you when Ink is low but I'd also check for gunk on the rollers that may have then sticking. The machine does check them but unlike with the ink you will get no "dirty" machine messages. It will just not ever be ready. Also, make sure you have no network printer software running if the printer is directly plugged it via the USB port. Only run that software if the printer is available via your local network. Simply stop such software and your printer will be available for local use again. I had to plug my HP printer directly into the new PC to install the drivers and have not moved it back to being connected to the router and the network printing software will interfere until I move it back.