I have a Retail CD of Arma 2 and Arrowhead on Steam. How do i activate CO?

[dbx125 1]

Help appreciated! I have the retail cd copy of Arma 2. I have it patched fully. I have Steam copy of Arrowhead.

How do I combine them? I know its possible since i did it before I just can't for the life of me remember how!

[Joe98 92]

Operation Arrowhead needs to be installed in the same folder as Arma 2.

You know you are successful when you start the game, open the editor and the maps of both games appear.

[JetlinerX 1]

Like this.

http://www.armaholic.com/page.php?id=8241

Go to second tab, link OA and A2 .exe directories. Go to tab 1, drop down box in bottom right, select "ArmA2CO" and WHAPOW! You're playing CO. Enjoy.