THIS GUIDE IS OBSOLETE! USE https://zombies.nu/community/threads/10693/ INSTEAD! ILL LEAVE THIS HERE FOR A WHILE IF SOMEONE WANTS TO ROLLBACK TO 11653 FOR REASONS UNKNOWN. If you are having problems installing the Arma 2: Operation Arrowhead Beta version 1.63 Build 11653 just go by these steps and you should be fine. If you don't have steam check this out: https://zombies.nu/community/threads/10145/ 1 - Open Steam, go to LIBRARY. 2 - Go to Arma 2: Operation Arrowhead Beta PROPERTIES. 3 - Go to LOCAL FILES and click BROWSE LOCAL FILES. 4 - Explorer window appears. Open Expansion, shift-delete the beta-directory. 5 - Go back to Steam, click UPDATES-tab. Verify that updates are enabled. 6 - Go back to LOCAL FILES-tab, and click VERIFY INTEGRITY OF GAME CACHE. 7 - Let Steam verify, download and install the update. (If you want to be sure that it installed correctly, you can launch the Beta once from steam.) 8 - Start DayZero Launcher to view that you have the correct version. 9 - Receive BACON. NOTE: Make sure you have Arma 2 Operation Arrowhead and the Beta installed onto the same Steam(library)-directory.