Hi! I am so in over my head. Please be kind I'm trying to put Windows on my son's iMac 20-inch, late 2009, has 2GB, plenty of space. Tables state that my model is compatible with Windows 7, 32bit - only. But would rather use Windows 8 or newer. He will be gaming. Just updated to El Capitan. Which Windows should (can) I install? Thanks so Much!