I have a Late 2012 2.5ghz i5 Mac mini running Mavericks 10.9.5. It was full of rubbish/old files and software etc. so I decided to wipe it and do a fresh/clean install (via my wireless connection), following the steps as shown below: All worked fine and the new install started but showed it would take 40+ hours to 'download components' after which it would restart and finish the Mavericks install. I quit the installation - to try again/resume when more convenient - and shut down the mini. When turning the mini on today, on start up I see a pale grey screen with a folder icon with a question mark: no surprise as obviously there is no OS on the machine. How do I get the OS back on the mini?