I have a 2010 MBA that is currently running Yosemite. I need to install Windows in Boot Camp mode on it, but the only legal copy of Windows I have is of Windows 7. Can I install Win 7 in the Boot Camp partition to go with the Yosemite? Is this process done more easily with a clean install of El Capitan and using Boot Camp in the latest version of OSX? If so, are there simple instructions to do this somewhere? I have never done a clean install or a boot camp install before.