If you have deleted one or more of the default Smart Bookmarks folders, including:

• Most Visited
• Recently Bookmarked
• Recent Tags

you can restore them by doing the following:

1. In the Location bar, type about:config and press EnterReturn.

   • The about:config "This might void your warranty!" warning page may appear. Click I'll be careful, I promise!, to continue to the about:config page.
2. Search for the preference browser.places.smartBookmarksVersion.
3. Double-click on browser.places.smartBookmarksVersion and change the value to 0 (zero).
4. At the top of the Firefox window, click on the Firefox button and then select ExitAt the top of the Firefox window, click on the File menu and then select ExitOn the menu bar, click on the Firefox menu and select Quit FirefoxAt the top of the Firefox window, click on the File menu and select Quit

The next time you start Firefox, the default Smart Bookmarks Folders will be re-created.