I'm needing to make a bootable W8.1 USB to install W8.1 on a brand new PC. Can I do this from/with my rMBP running Mavericks? I have the W8.1 key. Do I just need to download the ISO from Microsoft? Anything else? I'm (obviously) new at this ... never built a PC before, just bootcamped my Macs. edit/update Figured I'd update for anyone trying to do the same. I missed the obvious option: Boot Camp Assistant will give you the option to create a bootable USB. Super easy, I overthought it.