Title says all. I've spent about an hour trying to figure out how to install Windows 7 on my 2012 MBA with USB (this is after making a post about why people have issues with BC...now I see why ) and after a brief search, someone said that the BRAND of USB used to make the boot disc from the ISO matters. I can definitely confirm that. I made the bootable USB through Boot Camp Assistant -- apparently there's a new option that allows you to make the USB from OS X. I first tried with a USB 3.0 Sony MicroVault Mach 16GB stick, but I kept on getting the non-bootable message. I then switched to a Sandisk Cruzer Blade 8GB stick, and that did bloody wonders. If there's anyone having issues with trying to make a bootable USB for installing Windows 7, try a different USB disc.