Video Codec Help!?

Someone Please Help Me!!! Im Trying To Watch A Video, FFAC, And The Vido Doesnt Match The Audio, Someone told me to try a decoder or filter or something, but the audio is ahead of the video, and the video skips tring to catch up with the audio. WAT SHOULD I DO PLZ HELP!!!

If is a trailer you need Flash Player: http://www.macromedia.com/software/flash/about/ or go here and download VLC and BSplayer play almost everything.http://www.free-codecs.com/