I am unable to play mp4 file in Windows Media Player 11

[BlackSunReyes]

Hello, I have Windows Vista Ultimate 64 bit edition OS. Now whenever I try to play any mp4 file video, it doesnt plays in wmp 11. If I rename the file extention of the .mp4 video file to any other like .dat, it plays fine without any problem. I always get the error message "windows media player encountered a problem while playing the file" if I try to play it in Windows Media Player 11. Can anyone help me out solve this problem. Thank you

[unidentified]

You probably have not installed the correct codecs for your player.
Download and install K-lite Codec Pack Update 20090314. That might solve your problem.

[Viceman]

Alternately you can also choose another player to watch the .mp4 video file format. Download VLC Media Player version 0.9.9. The VLC package already includes software to play MP4 files and supports decoding a lot of video and audio formats out of the box.

[Expertz]

You probably miss directshow audio & video decoder for the audio & video streams and a splitter for the container. I would recommend:
a. use a player that comes with the needed decoders by itself (like SMPlayer, VLC, ffmpeg)
or
b. if you want gpu support during decoding, buy CoreAVC or Cyberlinks AVC Decoder + CoreAAC or an other AVC Decoder + (Haalis Media Splitter for the container comes with CoreAVC or you use the splitter that come with Cyberlink software)
or
c. use Haalis Media Splitter and ffdshow