Hi 1. A Firefox profile stores all of your important data, such as your bookmarks, history, cookies, and passwords. If you've lost your Firefox settings, bookmarks, or saved passwords after updating or reinstalling, you might still be able to recover them from an old profile. The article [[Restore bookmarks, passwords and data from an old Firefox profile]] explains how to locate your old Firefox profile and copy important data into your current one. 2. If Firefox starts up without your bookmarks, passwords, saved tabs and other settings, check whether your data is available in a different profile. This can happen because Firefox creates a dedicated profile for each installation of Firefox. To recover your Firefox data and settings from another profile see [[Recover user data missing after Firefox update or reinstall]]