Why can i only view tmd movies
 

When I download a movie and launch it my default windows media player pops up and plays the movie. It will only play tmd movies and when i try to play another kind of movie i can only hear it i can't see anything. How can i fix this problem?

I myself have never downloaded a TMD file, simply because I have never wanted anything like that (I mostly use Limewire for music) but I was reading that you should use a divx player (that has codec) and that should allow you to play it. I was also reading that with programs such as quicktime, windows media player etc. will only give you the soundtrack to the file.

It is a codec issue...
Try installing the VLC media player, it has all the codecs pre-installed and can play just about all files...
VLC media player - Overview

Get one of these pacs also...
For XP this codec pac is very good
Download XP Codec Pack 2.0.8 - XP Codec Pack is one of the most complete codec pack
Or for Vista this pac
Vista Codec Package v4.4.7 Beta 4a (freeware)

Another tip to try is sticking with avi files and check them with Bitzi before downloading...
How to use Bitzi Web Lookup .. & How to use Magnet Links & Direct Connect/Browse/Chat

Never heard of TMD movie files until now, is the quality any good?

It's a Nic, like a signature for files...
TMD must use a particular method to rip...;)