Access MWIII, Warzone and MWII and manage files with Call of Duty HQ. Call of Duty HQ was developed to bring players benefits like Carry Forward, easier file size management, and more seamless switching between Call of Duty: Warzone!" and the latest annual releases.
In other words, rather than have a single hub for all these games, Activision has created two but you can't access Modern Warfare II, Warzone or the DMZ without first accessing the main Call Of Duty HQ app!