I am very skeptical about this. I have been using Windows since DOS, and never had a completely successful version upgrade. I've always had to do full OS upgrades from scratch on an empty disc, and then spend weeks migrating my user data afterwards.
Maybe because my OS system is always modded beyond the OEM features. I'm sure I will have to re-install at least a dozen or more programs. Not to mention all those passwords to write down and re-enter. I don't have a spare drive to make a backup image of my current setup.
All this takes away from practice time which I just dread.
You can install a new full OS as well, just use you Windows 7 or 8 key. If you really dont trust it use a different drive anf if you dont like the results you can always just put the first drive back in.