Backing Up & Restoring Firefox in XP, Vista, or Windows 7

For an easy way to backup Firefox, use MozBackup, a backup and restore utility:  http://mozbackup.jasnapaka.com

The following will manually backup the FireFox web browser:

First find the Firefox Profile data directory:

1. For Windows Vista and Windows 7:  Click the Windows Start button, and type %APPDATA%\Mozilla\ in the search box at bottom of the Start menu, without pressing Enter.  Then click the Firefox folder in the search pane.
2. For Windows XP:  Click the Start button, and choose Run and type %APPDATA%\Mozilla\Firefox\ in the field and click ok.

Backing Up Firefox.

1. Exit Firefox
2. Browse to the Firefox directory above.
3. Right click on the Profiles folder and choose Copy.
4. Right click on your flash drive, backup drive, CD, or DVD and choose Paste to copy/paste the backup into your backup media.

Restoring Firefox:

1. Install Firefox, and restart it, then close it.
2. Browse to your backup file of Firefox
3. Copy the backup Profile folder
4. Browse to the Firefox directory above
5. Replace the Profile folder with your backup by copy/pasting it in there.

More instructions can be found at:
http://support.mozilla.com/en-US/kb/Backing+up+your+information