Sync can be slow. If you want to see what is stored on the Sync server, you can install the following add-on: https://addons.mozilla.org/firefox/addon/about-sync/ After installing that add-on, type or paste '''about:sync''' in the address bar and press Enter to load that internal listing page. It's a little hard to read, but for each type of data, you can see what is on the server. ---- '''''Recovering Data from an Old Drive''''' First, set Windows to show hidden files and folders -- this Microsoft article has the steps: https://support.microsoft.com/en-us/windows/view-hidden-files-and-folders-in-windows-97fbc472-c603-9d90-91d0-1166d1d9f4b5 Then if your old drive is attached as, for example, the E drive, explore the old drive along this path: E:\Users\<windows-username>\'''AppData\Roaming'''\Mozilla\Firefox\Profiles\ If you find recent data there, please pause and we can suggest how to transfer those files.