The About Mozilla Firefox window will open, and Firefox will begin checking for updates.
If an update is available, it will begin downloading automatically.
Software Update is available in Firefox, Thunderbird, and Sea Monkey 2.
This article describes how to configure and run Software Update and discusses problems that can occur during or after an update.
When an update is found, follow the on-screen instructions to download and install the update.
Any time you do an update or uninstall you have to restart Firefox for it to take effect.
If you uninstall an extension that you want to reinstall, go to the source where you downloaded it from to be able to reinstall it again.Since we have a number of popular Firefox extensions, I frequently get asked how to update Firefox extensions.