WARNING: The forum is now in read-only mode as we will soon be transitioning to different forum software. Feel free to join our Discord server in the meantime.
You need to have the base game. If the base game is deleted you have to re-downlaod. If the base game is on another drive, or you have a backup of it, you need to install origin, put Battlefield 3 in the "Origin Games" folder and verify Battlefield as a installed program