Do you have any backups of your Firefox profile folder? You might need one to restore your history. History and bookmarks both are stored in the places.sqlite file. There are third party utilities to let you work with this kind of file, but the FAQ on the official SQLite site is not very encouraging: "If you do not have a backup, recovery is very difficult. You might be able to find partial string data in a binary dump of the raw database file. Recovering numeric data might also be possible given special tools, though to our knowledge no such tools exist. SQLite is sometimes compiled with the SQLITE_SECURE_DELETE option which overwrites all deleted content with zeros. If that is the case then recovery is clearly impossible. Recovery is also impossible if you have run VACUUM since the data was deleted. If SQLITE_SECURE_DELETE is not used and VACUUM has not been run, then some of the deleted content might still be in the database file, in areas marked for reuse. But, again, there exist no procedures or tools that we know of to help you recover that data." http://www.sqlite.org/faq.html#q20 For future reference: [http://support.mozilla.com/en-US/kb/Backing%20up%20your%20information Backing up your information | How to | Firefox Help].