How do I add an application to Firefox's list of known apps?

Solution 1:

Click "Browse...".

Solution 2:

I had a problem with this procedure because I needed to add commandline parameters on the end of the application's file path, e.g "c:\program files\counterpath\bria.exe" -dial="%1"

So thanks, Kokbira, for providing the link to http://kb.mozillazine.org/The_associated_helper_application_does_not_exist , which states:

"Mozilla applications stores file type and helper application associations in the mimeTypes.rdf file located in the profile folder. Sometimes you might not see an entry for the problematic file type in the Download Actions or Applications list or the listing itself might be completely empty. In such cases, exit the application, open your profile folder and remove (or rename) the mimeTypes.rdf file. (Don't delete the "default" mimeTypes.rdf file in the program folder by mistake.) A new copy of the file will be generated when you restart the application. You should then be able to download again without receiving the error but any previously set download actions will be gone. "

Solution 3:

Do as @nik and @jon2512chua, because you cannot add directly an application to the list in Firefox, but only by that way; once you did it for a file extension, the program will stay in that list (called Helper Application).

More info, go there: http://kb.mozillazine.org/File_types_and_download_actions

If there are some errors when opening with an application on Helper Application list, follow procedures: http://kb.mozillazine.org/The_associated_helper_application_does_not_exist