Unable to launch Modern Warfare 2

Issue

Each time I try to launch Modern Warfare 2, I'm getting this error message:

"Please make sure Modern Warfare 2 is run from the correct folder " 

Solution

• In Steam: Right-click the single player mode or multiplayer mode of Call of Duty then go to Properties> Local Files> Verify the entire cache of the game ..
• Steam will check if any files is missing and download them.