How To Restore Mozilla Firefox

Mozilla Firefox

Mozilla Firefox is an excellent Web browser, fast and capable, but you might suddenly find that your settings (bookmarks, tabs, plugins, etc.) have gotten corrupted or even lost. This unfortunate problem can normally be fixed with Windows Vista or Windows 7 using the following procedure:

1. Close any Firefox windows that might be open.
2. Click Windows Start at left end of Task Bar, put the following in Search Box or Run, and press [Enter]:
        %LOCALAPPDATA%\Mozilla\Firefox\Profiles
   That should open an Explorer window with at least one Profile folder.
3. Right-click on a Profile folder, and then click "Restore previous versions" in the pop-up menu to open the Properties window.
4. Click to select the top (most recent) version, and then click "Restore...".
5. That should pop up a confirmation window ("Are you sure you want to restore..."). Click Restore.
6. Windows should then copy a bunch of files to restore Firefox, finishing with
   "The folder has been successfully restored to the previous version."
7. Click OK to close the message, then close the Properties and Explorer windows.
8. Launch Firefox.

Notes:

1. "Restore previous versions" does not exist in Windows 8. Use File History instead.
2. This procedure is covered in Windows 7 Help and Support under "Recover lost or deleted files" in the section "To restore a file or folder to a previous state". 
3. This only works if you have System Restore enabled and/or have used Windows Backup.
4. You can try restoring an earlier version if necessary.
5. If this doesn't work, you can start over by closing Firefox and deleting the Profile folder.

See also How To Restore Google Chrome.