You need to remove the read-only attribute from the folder where you installed the game and from all its subfolders. Right-click the main folder (for example mine is F:\CODWW2) properties, remove check in read-only, apply and on the next screen make sure you keep checked "Apply changes to this folder, subfolders and files" then ok. Next in security tab edit permissions and give Users full control over the folder. Then launch the game.
