Greetings Baddawg,
Please make sure CoD is installed in the default location (C:\Program Files (x86)\Call of Duty Modernwarfare). If it is installed in a different location move the game folder to “C:\Program Files (x86)” after completely closing down the Battle.net app. If issue persists also try the following solutions:
• Ensure the game does not have Run as administrator option checked in the game’s .exe file properties
• Delete the cache and tools folders to automatically rebuild outdated or corrupt files:
• Delete the Call of Duty folder located in Documents ( C:\Users\your_username\Documents). This will reset the game settings.
• If you are running CoD with any command line arguments try removing them. You can do that in the Battle.net desktop app under Game Settings.