I have multiple torrent programs installed and when I download a
.torrent file (in this case an Ubuntu ISO) using google chrome and open it, it doesn't open in my preferred program. How can I change this?
Show it in the folder, right click on it and go to the Open with another application. There you can select wiht what app. you want to open the torrent and then just check 'Remember this application for "Bittorrent seeds file" files'. This should work.