Microsoft can't prevent piracy of Windows itself, there's no way in hell they could ever implement a system to prevent PC game piracy.
Ironically, DRM has probably increased piracy, by a lot. I know after having my legit store bought copy of Spore hate me and think I was pirating it, I said screw it and headed to the Pirate Bay, and actually pirated a copy of it.
I find it ironic that my legit copy thought I was pirating it, but my pirated copy thought it was legit.
I'm not sure there really is a solution to PC piracy. About the best they can do is to make legit copies run easy enough, as not to encourage people to pirate it to get a better copy.










