Do you mean that you deleted the profile folder in "AppData\Roaming" ? If your profile isn't in the Windows recycle bin and you do not have a backup copy of files like logins.json and logins-backup.json and key4.db and this data also isn't in Sync then I'm afraid that your personal data is lost. *https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles *https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile *https://support.mozilla.org/en-US/kb/recover-user-data-missing-after-firefox-update