LW's media player is only an audio player. It does not play video. So when you preview a video file your default video player for that format will open & play it. Have you set your defaults for the different formats so when you double-click them fromthe desktop the appropriate vdeo player opens? Highlight a video file on the desktop, go to File > Properties & Open with... After setting all the different defalts for wmv, mpeg, avi, etc. then you won't have any problems launching.