I've heard much bad about Windows 8, but a little bit of good. I'd like to take advantage of the "free" (after rebate) offer for the upgrade to Windows 8, but I'd like to be able to go back to Windows 7 if I don't like Windows 8. I Googled and saw that I can create a System Repair Disc by using an external DVD burner or hard drive, but that won't do a complete install, right? Also, I would have no license key. Help?