Otherwise, there's no reason to keep the old folder except research/curiosity. If something essential is missing, look in these folders: Note: Some plugins may exist only in that OldFirefox folder. It should automatically connect to your existing settings.
(D) Run the installer you downloaded in (A). (32-bit Windows folder names) C:\Program Files\Mozilla Firefox (64-bit Windows folder names) C:\Program Files (x86)\Mozilla Firefox (C) Rename just the current program folder, either: There are some residual files that are not removed during. The very first practice you must follow is to check the current.
CAN I UNINSTALL MOZILLA FIREFOX SOFTWARE UPDATER UPDATE
(Scroll down to your preferred language.) Uninstall the already installed copy of Firefox installed on your system. You can use the Ubuntu command line terminal to update the Firefox to the latest version. You may also have to change a default browser, but this is optional. If the search digs it up, click the End Task button at the bottom of the page. (A) Download a fresh installer for Firefox 41.0.2 from to a convenient location. The uninstall wizard will display an overview screen with the location where Firefox will be uninstalled. Use the Ctrl+Shift+Esc to open it, then try to find the Mozilla or Firefox associated process. Do NOT uninstall Firefox, that's not needed. As described below, this process does not disturb your existing settings.
We use this name, but it's not about removing your settings, it's about making sure the program files are clean (no inconsistent, corrupted, or alien code files). Sorry, but there's no way to roll back an update except by downloading a fresh installer.