HI Debbie, two thoughts: (1) When you started Firefox, did it mention having to create a new profile? Either way, please try the steps in the first section of this article: [[Recover lost or missing Bookmarks]] (2) Did the upgrade create a folder named C:\Windows.old If so, that's usually a temporary folder which gets deleted after 28 days. Turn on viewing of hidden files and folders -- https://support.microsoft.com/en-us/windows/view-hidden-files-and-folders-in-windows-97fbc472-c603-9d90-91d0-1166d1d9f4b5 -- and explore up the path to C:\Windows.old\Users\<username>\AppData/Roaming\Mozilla\Firefox Is there data there? If so, we can suggest how to restore this to the new locations.