Launching with ITunes

I turned off the Limewire player and so it should automatically launch with my ITunes default player...but it won't! If I share it with ITunes (which is in the options tab) it'll work but it will only work with Limewire on...it won't add the music into my ITunes library which I would like it to so I can make playlists and download to my ipod and such. I used to have limewire and it automatically played the music I downloaded and added it to my library. Now it won't. What should I do?