WD My book Elite + WD TV Mini Media Player... how to veiw movies on tv

I have a External hard drive which has 300gb of movies on it and I got the mini media player so I could watch them on my TV.

Everything is plugged in and ready to go but I can’t find the movie files on the tv through the wd file management.

The manual tells you to go into file management and click on videos and then manage it all through there but the movies that are on the hard drive don’t show up when it’s plugged into the media player and TV.

Is there something I am supposed to do with the My Book elite on the computer before hand?

If not then what else could be the issue?!

Thanks.

I have only had this problem when it is an unsupported file format .  What file format are they?