This error typically happens when a shortcut or executable is trying to start the game from a directory like \bin instead of the main game folder, or if essential files are missing after a patch.
: This is the most reliable method for official Steam or Battle.net versions.
The transfer was agonizingly slow. 10%. 20%. Outside, the rain intensified, thunder rumbling over the city. The lights in the café flickered.
Your anti-virus (Avast, McAfee, Windows Defender) quarantined it. Add your entire MW2 folder to the antivirus exclusion list.
Once you have the file, you need to put it in the right spot.