First: Navigate to your "arma 2 operation arrowhead/Expansion/BattlEye" folder. Following this, run the uninstall.exe
Now the folder should be deleted. Go back to the "Expansion" folder and delete the "beta" folder.
once this is done, go to your arma 2 folder and uninstall BattlEye here too. This is found in arma 2/BattlEye.
Once you have deleted your beta folder and uninstalled both BattlEye's in arma 2 and arma 2 operation arrowhead, download the latest beta patch (however I think it's a little shifty at the moment, so 94876 will do). Now run the Beta .exe and it should stop at 3% and ask you to install BattleEye - do so. Once BattleEye is installed, complete the installation of the beta patch and you're ready to go!
Good luck!
**EDIT**
Go to your arma 2 oa folder > open Expansion > open BattlEye and run the uninstall.exe
Go to your arma 2 folder > open BattlEye and run the uninstall.exe (if it isn't there, don't worry about it)
Run the game with (the beta should still be installed - doesn't matter what one)
Try to join a server - you should get stuck at either Loading or Wait for Host - this is normal
Close the game and go back into your arma 2 oa folder > Expansion and delete the beta.
Download and install beta patch 94700
It will ask you to install BattleEye, do so.
Go into your arma 2 folder > go into BEsetup and run the .exe
Go back into your arma 2 oa folder > Expansion> beta and copy the BattleEye folder (DO NOT CUT OR DELETE IT - YOU ARE MAKING TWO COPY'S OF IT).
Paste the BattleEye folder in the main arma 2 oa directory.
Open arma 2 oa and join a NORMAL arma game. Any will do, as long as it is NOT DayZ and it has BattlEye active.
Once in, abort and close the game.
Download and install beta patch 94876 and install it.
Open arma 2 oa and join a DayZ game.
Edited by Rammfisch, 14 July 2012 - 04:34 PM.












