How can i change the default download setting for music?

i'm trying to download with Utorrent and The Pirate Bay, but every file i try to download automatically downloads as Type: LimeWire, Torrent eventhough i uninstalled LimeWire some time ago. I tried to use a format converter the softwares i've tried don't recognize the file therefore cannot convert them. How can i either change the defult download setting or convert them. i have windows vista and WMP 11.