|Right-click on the main toolbar, and a list of "available" toolbars will display, with check-marks for the enabled ones, and no check-marks for the disabled ones. If "New02" is un-checked, you can simply re-enable it by "check-marking" it.|
Firefox also regularly makes a back-up of your bookmarks, at:
C:\Documents and Settings\username\Application data\Mozilla\Firefox\Profiles\nnnxxxxx.default\bookmarkbackups\bookmarks-yyyy-mm-dd.json. To import the backup:
From Firefox, select Bookmarks, Organize Bookmarks...\Import and Backup (button)\Restore > Month Dd, YYYY.