Windows & Mac Codecs

Ever had a movie where you could only hear the sound and there were no video? Or vice versa? The problem lies with you not having the right codec installed.

For Mac users, Perian is a free and open source QuickTime component that adds native support for many popular video formats.
If you’re using Windows, CodecInstaller is great but it requires Microsoft .NET Framework 2.

Another way is to use VLC Media Player which is simply brilliant.

VLC media player is a highly portable multimedia player for various audio and video formats (MPEG-1, MPEG-2, MPEG-4, DivX, mp3, ogg, …) as well as DVDs, VCDs, and various streaming protocols. It can also be used as a server to stream in unicast or multicast in IPv4 or IPv6 on a high-bandwidth network.