Please don't name the files, it's against the 
Forum Rules  
If you launch the file from LW, it should run in your default media player. See 
Setting Default video app.  
If it wont play, you may be missing the proper codecs to play the file. You could try using a different media player, 
 VLC media player is a good one that has the codecs built in. More info here 
CODECs list for Movies /Alternate players / Video help forums.  
XP Codec Pack 1.3.2 is a good one for windows media player. 
Also a lot of movie files on the network are bad/fake/corrupt. Bitzi Web Lookup can help you find good files. See 
How to use Bitzi Web Lookup ... & How to use Magnet Links & Direct Connect/Browse/or Chat 
Hope this helps