Make sure you are running:

1.15 Beta Patch
ACE Mod
Avgani map
Afghan Village map
ACE Islands

Also make sure you've changed your command prompt of your shortcut to enable the mods/patch

Code:

"C:\Program Files\Atari\ArmA\beta\arma.exe" -mod=beta;@ACE;@Maps;@ACE-Islands -nosplash

How to use the modfolder method:

Option 2 : Modfolder method
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We can use this method so we just load at the startup the addons we want to use, saving loading time, avoiding incompatibilities, ...

I will use the FDF Sound mod as an example:

First we have to create 2 folders inside the main ArmA one. We create a folder called @FDF_Sounds and inside this one another called Addons.

Inside this new Addons folder we place the .pbo file(s), in this case the FDF_Sounds.pbo and FDF_Sounds_c.pbo files.

NOTE2: If the download contains any .bisign file they should go to the same folder you place the pbo ones. This .bisign files are there so players using properly signed addons can join to that server which requires them.



Now what we have to do it's edit the ArmA shortcut so the game launches using that addon. To do this, we do rightclick on the ArmA shortcut in the desktop or where we have it and select properties.
In the target box we add -mod=@FDF_Sounds as shown in the pic:



NOTE3: The pic its in spanish but its easy to find the analogies.
NOTE4: By adding also -nosplash we will get that the game launches faster as it doesnt load the intro movies.
NOTE5: To load more than one mod folder use semi-colons to separate then (-mod=@mod1;@mod2;@mod3)

More information on how to use modfolders here: http://www.armaholic.com/plug.php?e=faq&q=18