I'm trying to install Windows 7 Professional 64-bit onto my 2011 MacBook Air and it's having none of it. The problem seems to be the 64-bit ISO. I have downloaded it from 3 different sources now (MS student site with my uni, torrent site, and official MS site) and all 3 have problems when it comes to mounting them and/or writing them to the USB drive. On Windows I'm mounting them using Daemon Tools Lite and whenever I try to run it Windows gives me errors about corrupted files. On OSX it just won't mount at all. I had no problems installing 32-bit Windows 7 using the exact same method. Can anybody help me out? Been trying this for hours now. EDIT: Thought I'd mention, the only reason I'm wanting to install 64-bit is so that I am able to use all 4GB of RAM when using Windows 7 as at the moment we are stuck with 2.7GB (I think).