You just need to go to the folder options for any folder and you can access the settings form there. Here's the long way around:
Go to Start > Control Panel > Appearance and Themes > Folder Options > File Types, in the window will be a list of file types, Scroll down the list till you find Torrent(TORR). Hi-lite it and go below the window where it says "Opens With" and click "Change". Find the program you want in the list. hi-lite it and click ok. That should be it. Try d/loading something and see if it works.
Sample picture here > > > http://www.gnutellaforums.com/attach...options-01.gif