When gamers around the world boot up their Xbox One systems to play Call of Duty: Ghosts for the first time today, the system will do a careful hand-off behind the scenes that involves three separate operating systems developed by Microsoft. This is a new one for the software giant, which debuted its next-generation console today in 13 countries. The original Xbox and Xbox 360 did not run Windows, Microsoft's flagship computing platform. Previous iterations of the system had a single custom operating system focused primarily on playing games. The Xbox One has a game-centric ...