Hi guys, need a little help here. So I want dual boot Windows 7 with my already installed Snow Leopard on my Macbook Air, I'm using an external DVD drive, I start the Boot Camp setup, follow the instructions, create my partition and then it asks me to insert my copy of Windows, I insert my legit copy of Windows 7 Ultimate and after about 15 seconds an error message pops up that says "The installer disc could not be found", the disc doesn't have a scratch on it and I installed Windows 7 on my desktop Windows PC about 10 months back using this exact same disc so I know it works. Strange thing is, is that when I insert my copy of XP instead of Windows 7, it recognizes it right away and then installs just fine, I don't want XP though, I want Windows 7, anyone have any input regarding this matter or know what the problem is? Thanks