Files and photos are gone from Windows, or from a site you visited in Firefox? If any Windows data is missing, the first thing to try is a normal shutdown and restart in case for some reason Windows started up under the wrong user or without proper permissions. ---- If Windows did a major update or refresh recently, it may have stashed your previous data in a temporary folder (saved for 28 days) under C:\Windows.old '''Can you find such a folder on your system?''' ''If so:'' Before proceeding, please set Windows to show you hidden files and folders: https://support.microsoft.com/en-us/help/14201/windows-show-hidden-files Then check here: C:\Windows.old\Users\<username>\AppData\Roaming\Mozilla\Firefox\Profiles\ If you find recent data there, please pause and we can suggest how to resurrect your saved files.