The increased file size was "due to the increased amount of content" at launch, including map files for Warzone, as well as the Zombies mode, and the fact that a lot of content from Modern Warfare II carries over to Modern Warfare III.

Modern Warfare has been out for almost two years, and after continuous updates, the game takes up a huge amount of space. Here's why Modern Warfare's file size is so huge. Modern Warfare started life with a massive 175GB requirement to store on drives, making it one of the biggest games ever.