Automatic upgrade from Firefox 28 to Firefox 29 broke session restore and lost all my tabs in XP due to profile location change It looks like the Mozilla\Firefox\Profiles folder was moved from my "local data" to the "app data" folder and may have contributed to the mangled upgrade, guess FF29 is not ready for the public yet. My solution: 1) Use an undelete utility to recover a sessionstore.js file under my previous folder "local data" location, luckily they save frequently and I found plenty of good clean copies from just before the upgrade. 2) Follow the Firefox reset instructions and you should now have the session restore options. 3) Exit and then restore the sessionstore.js file to the new "app data" location. 4) Open and see the restored tabs for session prior to upgrade. 5) Customize the toolbar and put the "tab group" button back somewhere visible. Hope That Helps :^)