duplicate of [/questions/1108559] I found this to be the easiest way to restore old firefox data. If you ever had to do a complete refresh on your browser, once done you should see an "old firefox data" folder on your desktop. 1. open my computer or file explorer 2. navagate to C:/users/your computer name/appdata/roaming/mozilla/firefox/profiles/ 3. here you should see a default profile folder, open it 4. delete all data in that folder 5. open the old firefox data folder 6.copy all the contents of the old firefox data folder to the default folder 7. start firefox and all will be restored to normal before you did the complete refresh