If you are expecting addons to work, you should stick to the release version anyways, as addon develop theirselves for the release channel (most of them). SEE the [[Install Firefox on Windows]] article for installing release Firefox.

You can install multiple Firefox versions via a custom install in different installation folders and fallback to the release version in cases where the Nightly or Aurora build aren't working properly. Do a custom install and install each version in its own program folder to use multiple Firefox versions. * https://support.mozilla.com/kb/Custom+installation+of+Firefox+on+Windows * http://releases.mozilla.org/pub/mozilla.org/firefox/releases/ Make sure not to start Firefox after the installation has finished.<br /> Create a new profile exclusively for each Firefox version.<br /> Create a desktop shortcut with -P "profile" appended to the target to launch each Firefox version with its own profile. See also: *http://kb.mozillazine.org/Using_multiple_profiles_-_Firefox *http://kb.mozillazine.org/Creating_a_new_Firefox_profile_on_Windows *http://kb.mozillazine.org/Shortcut_to_a_specific_profile You can use the -no-remote command line switch to open another Firefox instance with its own profile and run multiple Firefox instances simultaneously. *http://kb.mozillazine.org/Opening_a_new_instance_of_Firefox_with_another_profile