Always create a backup of the original files in your game directory before you start replacing anything. This way, if something goes wrong, you can easily restore the game to its working state.
Your console or PC store account is set to a region where English is not the primary language. English Language Pack For Call Of Duty Modern Warfare 3
Steam will automatically trigger a download for the English language files. Do not launch the game until the download bar hits 100%. How to Install the English Pack on PC (Battle.net) Always create a backup of the original files
If you bought a region-locked version of the game (like a Russian key) and Steam prevents you from switching languages in the properties menu, or if you are running a non-Steam version, you may need to install the language files manually. Steam will automatically trigger a download for the
If you tell me your platform (Steam, Battle.net, PlayStation, Xbox, or PC without a launcher), I can give exact menu paths and screenshots-ready steps for that system.
Your console or PC client is set to a different primary language.