The last few Gears of War, Forza MotorSport and Halo games? None of them are playable on PC.
Microsoft has been promising to support PC gaming in a big way for a while now, but outside of their multi-billion dollar purchase of the Minecraft brand, available on every platform imaginable - including most recently with a Windows 10 edition - Microsoft is still failing to bring their biggest game exclusives to their own PC OS. But before that, Microsoft is also promoting their biggest video game release of 2015 in Halo 5: Guardians, the first new core Halo game on the Xbox One and only the Xbox One. It's the new infrastructure that will help connect PC to Windows Phones, Microsoft's latest Surface lines and of course, the Xbox One when the console's New Xbox One Experience update launches later this year. Microsoft is in the midst of promoting their new operating system, Windows 10, freely available as an upgrade to existing Windows 7 and 8 users.