Follow these troubleshooting steps in order to eliminate the frame restriction. 1. Disable Eco Mode Preset

If the game thinks your monitor is running at 90Hz (instead of 144Hz or 240Hz), it will cap FPS to half that rate. Sometimes Windows Update resets your refresh rate.

Locate the file named options.3.cod23.cst (or similar for the current MW3 build). Delete the file or move it to your desktop as a backup.

Edit config_mp.cfg: