you need to set the default options for which media program runs which media type (eg MP3, avi, wav etc).
There are a number of places you can set these options but the usually u can set it in "option" or "preferences" of the player you want to use as the default.
ever since i last updated my windows xp i am having problems loading divx movies on my media player. it is acting quite funny as sometimes when i launch the same movie with another player then media player plays the movie. please help if you know how i could get rid of this problem.