Open QT: Edit>Preferences>QT Preferences. Use the drop down menu to go to "File Type Associations" and then click the "File Types" button. You can then select which file types you want QT to play. I've not heard of it trying to play files that WMP handles as default before, though.
Open QT: Edit>Preferences>QT Preferences. Use the drop down menu to go to "File Type Associations" and then click the "File Types" button. You can then select which file types you want QT to play. I've not heard of it trying to play files that WMP handles as default before, though.