HELP ME! Nero 6 problem with visual!

Hey there,
new too this so have no idea what is happening but I have installed nero 6, downloaded a dvd & when it starts to play I can hear it perfectly but it is not showing up on the screen. Anyone have any idea where i have messed up here???
Many thanks
Katie

When you say that you downloaded a DVD, what exactly do you mean? And how and where did you attempt to play it?

Just need a bit more info.

sorry I meant i downloaded a movie from a torrent site. Well a couple & none work. I have tried playing it on is it nero showtime?? & have now also tried playing through windows media player which I am still having the same problem. The sound is there & no picture at all, To me it seems as though they are just audio files but they are def video files.

Ok, I get you now. What format are the movies in? AVI, WMV, etc?

Ive found that Nero showtime isnt a great viewer I would use vlc media player (http://www.videolan.org/vlc/) it will play most video files. Its also free, so thats a plus.