To play audio/video files downloaded from BT,you must have these software installed in your computer.
1>
VLC Player (Video Player)
2>
BSPlayer (Video Player)
3>
Windows Media Player 10 (Video Player)
4>
K Lite Codec Pack (You will never directly use this s/w but its needed to run the above two players)
5>
Winamp (I am sure everybody already has this!!)