VLC Media Player, a free to download, open-source multi-platform media player. You will not recieve anymore Codec playback error messages because VLC Media Player features the largest decoding and encoding libraries avoiding the need to download additional codecs.
VLC can play it all.
VLC also supports playback from damaged, incomplete, or partially downloaded files. With the preview feature you can preview playback of partial media files to check the quality of your video file. With VLC Media Player you can record High-Definition media content during playback of online streaming videos as well as DVD's and Blu-Ray's. VLC Media Player also supports the ability to record live TV using an external decoder card. VLC Player is Region-free. It can handle playback off all DVD regions without restriction. Besides from being able to play virtually any Audio or Video file you like, there is a lot more this light-weight and powerful media player can offer.
VLC Player is the number 1 media player out there. The latest version can be downloaded here.