Associating torrent files in Windows 7 64-bit
Add a batch file called Vuze.bat in your Vuze directory with the following contents: start javaw -classpath swt.jar;Azureus2.jar org.gudy.azureus2.ui.swt.Main %1
Double-click a torrent file on your computer.
If it is not already associated: Click "Select a program from a list of installed programs" and hit OK. Enter a file description of "Torrent" Continue with the "already associated" steps below.
If it is already associated with something else, Windows will prompt you with recommended and other programs. Click "Browse...", navigate to your new Vuze.bat file, and hit Open. Make sure "Always use the selected program to open this kind of file" is checked.
Try opening another torrent file, you should be good to go! :)