Well, I cant say much because the installer freezes on me... (ugh... microsoft). Hopefully someone else can help.... I just use VLC or other media players that can be found at http://www.macupdate.com/ and http://www.versiontracker.com/
Brian, throw out All the preference files for Windows Media Player (there are several). The program will run but if one chooses a different skin, it will crash at every launch. Time for an upgrade from Microsoft.