The LW Playlist function is "only" intended for audio files, not for video files. The LW media player is simply an audio player.

If you have the most recent Roxio version, it will convert the video files just the same as Nero does. But you need to check the settings to be sure it encodes at the right size & not too high an overall bit rate. Always do audio in dolby surround (ac-3) format otherwise the bit rate will be too high & your dvd will have problems playing.

I have the mac version roxio & it's very good. My version of roxio for windows is quite old. lol

As WW recommended, for previewing get VLC - (click on link) _ (choose nearest mirror site) as it is very reliable for video playback & has in-built codecs & will play all avi files.