The current wide variety of multimedia formats has become an issue when playing audio or video files. We often download videos from the internet which use different codecs and we do not always have the proper codecs to play them. How many times did you download an audio or video file just to see you couldn´t play it? Next, we will give you a short review detailing four different codec packs: K-Lite Mega Codec Pack, Codec Pack de ELISOFT, Combined Community Codec Pack and Vista Codec Package.