How to play mp4?

If the screen remains black, it's most certainly a missing codec. I suggest you installing CCCP Codec pack, you can find it at http://cccp-project.net

Install it, and use MPC HC isntead of VLC (definitely better, in my opinion)
 
VLC doesn't need any codec, there are all bulit-in. I don't use VLC either (don't like it to much...) :exhausted:

AS M. akuma2002 says, MPC HC + CCCP or satsuki decoder pack is the best choice. Only my point of view.

:tea: