Try putting your screen into 16:9 aspect ratio in game then save and exit.
Open up your steam directory.
Example from my pc:
X:\Steam\steamapps\common\MW3\Players\Multiplayerconfig.
Open the config with a text editor like word pad, find the resolution string, and type in your desired width and height, and also make sure the refresh ratio is at 60HZ.
Once you have set these values save and exit, then right click the CFG file and click read only.
Try putting your screen into 16:9 aspect ratio in game then save and exit.
Open up your steam directory.
Example from my pc:
X:\Steam\steamapps\common\MW3\Players\Multiplayerconfig.
Open the config with a text editor like word pad, find the resolution string, and type in your desired width and height, and also make sure the refresh ratio is at 60HZ.
Once you have set these values save and exit, then right click the CFG file and click read only.