Assuming you are talking about .ahf files...If you navigate on your harddrive to your htc\aceshighII\ folder, you will find "AHFilm.exe", open it and you can open AH films from there.
To make it so you can open ahf films by double-clicking them; on one of your films... right click-->open with... and from the open with... window, click other... and navigate to, and select AHFilm.exe
