EDIT:if I use a replacement disc with a code that I've already used to be the 2nd OS on a MBP, will Microsoft's servers know? I'm positive that I can upgrade from this disc to Windows 7(and once I upgrade, I won't be flagged for using an invalid copy, almost as if the source Windows is lost), but I want to know if I can use the disc in the first place. People will tell you that you're buying a MBP for the OSX, but I still want Windows 7 on it so that I can run Windows programs in the future. How will RC1 compare to the real version? Will it be noticeably faster, will there be any new features? I also hear that RC1 expires in Summer 2010 and that it will start shutting down your computer every 2 hours and whatnot. Will it mess up your MBP if you're on OSX (as in it will only send you that shutdown message if you're on Windows 7). I may or may not get Parallels or Fusion (which is better?), but running it on bootcamp is fine with me as well.