Hi, I've been using my mid 2012 rMBP with 10.8.3 all day. I came home, worked a bit more with it, turned it off and left it with my mom. 2 minutes later she calls me saying that the rMBP won't boot. It just hangs on the Apple logo with the spinning wheel. Right now I am using it to write this post under Windows 8 (Boot Camp) but I just can't get it to boot into OSX. I tried: - Resetting the SMC; - Resetting the PRAM; - Safe Mode (hangs on the Apple logo after the progress bar reaches 1/4); - Repaired Disk and Disk Permissions using Disk Utility under Internet Recovery. Nothing did it. It just hangs forever.. waited 5 minutes tops. I didn't install anything new. Just been writing an essay, watched some vídeos, surfed the web and that was it. College's almost finished, I have a ton of work to hand in and this crap happens right now. I know I probably will have to format and reinstall ML but I don't have time for it now. Plus, all the backups through Windows etc. Any help would be appreciated. Please. PS: I received the notification about the Thunderbolt firmware update but did not install it in case you wonder.