picture ok but there's no sound

I download some movies but the picture come out but there’s no sound. Please help me how to setup for the sound or is there anything else I need to download for the sound?.Please help me

Download and install:http://www.afterdawn.com/software/video_software/codecs_and_filters/ac3filter.cfm

thanx...

thanks!!!

picture but no sound what do i do in easy terms, as i am new to this. regards peter mara.