I have an MSDN subscription so I was able to download an .iso file of Windows 8.1 (and I have valid license keys to go along with this). What do I need to do with the .iso to prepare for installing Windows 8.1 using Boot Camp? Burning a DVD would be straightforward but the relevant computer doesn't have an optical drive. Do I need to make a bootable USB? How would that be done on a Mac computer? Alternatively, can I just use the .iso in Boot Camp without any other preparation?