It’s often important to know what version of Waterfox you are using, to help you troubleshoot a problem or just to know if Waterfox is up to date. Here is how you can find out. Click the menu button , click Help and select About Waterfox. The About Waterfox window will appear. The version number is listed underneath the Waterfox name. Here is an example of what the About Waterfox window will look like: Opening the About Waterfox window will, by default, start an update check. If an updated version of Waterfox is available, it will be automatically downloaded. For more information, see Update Waterfox to the latest release . Tip You can also find your Waterfox version on the Troubleshooting Information (about:support) page. Your Waterfox version is listed underneath the Application Basics section of the page. Source
Waterfox disables background updates on Windows. Updates are checked for and installed only when Waterfox is open. How to update Waterfox on Windows Click the menu button at the right side of the Waterfox toolbar, go to Help, and select About Waterfox. Waterfox will check for updates automatically. If an update is available, it will be downloaded. When the download is complete, click Restart to update Waterfox. Background updates are disabled in Waterfox Background updates are not available by design. Waterfox will update only when the browser is open. Source