please see if your old profile data is still accessible this way: https://support.microsoft.com/en-ae/help/17125/windows-8-restore-files-old-folder-upgrade [[Profiles - Where Firefox stores your bookmarks, passwords and other user data]]

Windows 10 has several options for what to do with your data when you use its Reset feature. One is to move it to a temporary folder named '''C:\Windows.old''' which is preserved for 30 ''{according to the above-linked article, only 28}'' days . Do you see anything like that? To explore that copy of the old user folder, you need to turn on viewing of hidden files and folders: http://windows.microsoft.com/en-us/windows/show-hidden-files Then look for C:\Windows.old\Users\''your-user-name''\AppData\Roaming\Mozilla\Firefox\Profiles If you find data there -- one or more semi-randomly-named folders -- there's a good chance of using that to restore your Firefox bookmarks. More details if found any folders... let us know.