It sounds like you’re looking for a legitimate way to obtain or repair for Call of Duty: Modern Warfare 3 (2011), specifically related to the zone folder. This folder contains the game’s core map, asset, and language data.
If you own a non-Steam legitimate copy (e.g., old disc version), consider registering your CD key on Steam to gain access to automatic file repair and language switching. Cod Mw3 Zone English Folder Download