If you did a Refresh you should have an '''old Firefox data''' folder on the desktop. You should restore those files to your Profile folder. https://support.mozilla.org/en-US/kb/refresh-firefox-reset-add-ons-and-settings At the bottom: <blockquote>Note: Your old Firefox profile will be placed on your desktop in a folder named "Old Firefox Data". If the reset didn't fix your problem you can restore some of the information not saved by copying files to the new profile that was created. If you don't need this folder any longer, you should delete it as it contains sensitive information. </blockquote> See this - [https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile#w_copying-files-between-profile-folders copying files to the new profile that was created.] ---------------- As far as '''"back in the day"''' ... Both the old version of Sync and the latest version used the users email address as the account name. Prior to Firefox 4.0 when Sync was made part of Firefox, with the old Weave extension a separate user name was used. If you were using Weave and then updated that ancient account to Sync in Firefox 4.0, and then upgraded to the new Sync that came with Firefox 29.0 - and you don't have the old long string username or the email address - you're pretty much outta luck. As I recall, a long ~20 character alpha string was created 4 months prior to the release of Fx 4.0 version (with the now "old" Sync) when updating an ancient Weave account to replace the user created '''''user name''''' in lieu of the email address which was used for new accounts that were created after that change. (like mid-December 2010)