MP4 in Windows Media Player 11

Tried to play an MP4 file today on my Windows Vista Pro, Media Player 11 machine and wasn’t able to (it was generated by Jing, which is cool by the way, but it would be nice if it made a more common file format available for sharing). 
Anyways, I was able to find the Vista Codec Package 5.1.4 here – ( and after installing it, I was good to go.