A few things to check:

Make sure your Black Ops 2 game folder contains t6zm.exe and/or t6mp.exe.
In the launcher settings, set the Game Folder to the folder that actually contains those files, not the parent folder.
If you're using Steam, make sure BO2 has been launched at least once through Steam.
Try closing the launcher completely and running it as Administrator.
If changing the game folder doesn't help, can you post:
A screenshot of your launcher settings
The exact path you're using for the game folder
Whether you're using Steam, a backup, or another installation method

That information would help narrow down why the launcher still thinks it needs setup.