MS has not thought of it as your computer for quite some time. Vista took away your control further in order to please the movie industry which does not trust anybody (if they could, they'd require a memory zapper so we couldn't remember films we've seen without paying a fee.)
That would actually be kind of cool...
I mean, there's the obvious jokes to be made ("zap my memory so I don't remember the Matrix sequels", etc.) - but apart from that fun nonsense, there are times when I find myself wishing that I could approach a familiar movie with a totally fresh perspective.
The original Star Wars trilogy comes to mind. I saw those movies when I was very young, and repeatedly (on TV) - I wonder what I would have thought of Yoda's introduction if I didn't already know who he was, or the various revelations about the Skywalker family in the second and third films. It would be neat to see that stuff with a fresh perspective. Of course there's the possibility that I would be extremely disappointed with the experience, too. *shrug* But sometimes a story can be so familiar, either because I already know it or because of various forms of incidental exposure (like movie trailers) that I wish I could just go in without any preconceptions.