%APPDATA%\Mozilla\Firefox\Profiles

Here are a couple places to look for session history files: (1) Post-Reset/Refresh Profile folder Do not quit Firefox! If you already quit Firefox, do not start it up again! Please back up your session history files to a safe location for potential recovery/salvage operations. ''If Firefox is running now:'' You can open your current Firefox settings (AKA Firefox profile) folder using either * "3-bar" menu button > "?" button > Troubleshooting Information * (menu bar) Help > Troubleshooting Information * type or paste about:support in the address bar and press Enter In the first table on the page, click the "Show in Finder" button. ''If Firefox is NOT running now:'' ''Call up the Run dialog (Windows key+r or the programs screen) and type or paste the following, then press Enter:'' %APPDATA%\Mozilla\Firefox\Profiles ''Then double-click into the most recently updated semi-randomly-named folder you find there.'' ''Next Steps whether Firefox running or not:'' In the window that launches, scroll down and double-click into the '''sessionstore-backups''' folder. Save all files here to a safe location, such as your Documents folder, so Firefox doesn't overwrite them. We may be able to use them to recover your lost tabs. Also, if you return to the main level of the profile folder, you may find some sessionstore files. Copy those to the safe location as well. Could you report back on what you found? (2) Pre-Reset/Refresh Profile Folder This is the folder inside the Old Firefox Data folder on your desktop. What do you find in the '''sessionstore-backups''' file here (e.g., recovery.js) or at the main level of the folder (e.g., sessionstore.js)? ''Note: If Windows hides the .js file extension from you, you can change a setting so that you can see all file extensions (this helps when renaming files). This support article has the steps: http://support.microsoft.com/kb/865219 or http://windows.microsoft.com/en-us/windows/show-hide-file-name-extensions'' ---- The kinds of files you may find among your sessionstore-backup files are: * recovery.js: the windows and tabs in your currently live Firefox session (or, if Firefox is closed, your last session) * recovery.bak: a backup copy of recovery.js * previous.js: the windows and tabs in your last Firefox session * upgrade.js-''build_id'': the windows and tabs in the Firefox session that was live at the time of your last update Could you take a look at what you have and the date/time of the various files to see whether you think any of them would have the missing tabs?