If you can't play a video file with a non-common codec on your usual media player, VLC Media Player may solve your problem.

This free software edited by Apple is an absolute must-have, probably one of the best audio players.

Edited by Nullsoft, Winamp is a fast and reliable freeware which can play almost all the audio (mp3, wma, ogg, wav, cda...) and video (avi, wmv, mpg, divx, xvid...) files.

With this free audio editor, you can not only record and play sounds, but also import and export WAV, AIFF, MP3, and OGG files.

RatDVD is an incredible and unique freeware : it can take all the features of a DVD movie and convert them into a single compressed file, which will be readable by a classic player such as Windows

Super © is a free and yet very efficient tool, designed to let you easily convert or play all types of multimedia files, practically all the existing audio and video formats.