Hello, i am trying to update my Arma 2 OA to 1.60 using the latest update but it is stating that "ARMA 2 OA is not installed on your computer or installation is corrupted, But the thing is that i do have the game installed both arma 2 and Arma 2 oa and the update ARMA2 patch 1.11 installed fine without this error and i am stumped by why it is doing this can some one help me out.