From what I can tell everybody has been having this problem, Nero 7 conflicts with windows media player when it comes to playing some media files, specially DIV-X and X-VID files. From what little I could gather, it isn't a file associating problem, it isn't a codec problem either. I think the problem is related to a plugin that Nero installs called "Nero Digital Audio Decoder". Now if someone with the knowledge to solve this problem could help me and all those other people who have been struggling to figure this issue, we would be very happy. Let me thank you in advance for any light you can bring on this thing.