Codec Pack Advanced is a collection of codecs, mainly designed for people who want to encode video and audio.
This will also be useful for anyone having playback troubles, as the collection of codecs is pretty comprehensive, though there is much more here than is necessary for that.
There are over 30 codecs included in Codec Pack Advanced, from DivX and Windows Media Player, to Huffyuv Lossless Video codec and much more. The developer recommends that you uninstall any previous codec packs you have, to avoid possible clashes. The installation will allow you to play almost any video and audio file, and also encode files if you wish. There are also tools to play and backup/copy protected CDs and DVDs
Unfortunately, during installation you are forced to add a toolbar, and although it can be removed later, it's an unnecessary irritation.
Codec Pack Advanced has pretty much everything you'd need to play and encode audio and video.
