Visit the author's site and download the latest version (1.5.1 as of this writing) if you do not have it. You can use either version: standalone or the Windows installer version. I would suggest using the installer version which will facilitate frequent backups on the same system.
The standalone version is great for use from a USB stick which can be used to backup the user's information from one computer and import it onto the next.
Backing up Mozilla Firefox is straight-forward. Most users will simply keep hitting
Next throughout the process.
Next from the welcome screen, you will be presented with the software selection menu.
Select the software you would like to backup,
Firefox in this case.
The default selections will typically ensure that a restore from the backup will function identically the same as the current setup.
The backup process will take from a few seconds to a several minutes based on the amount of information to be placed in the backup.
Upon completion a report will be presented which summarizes the items backed up.