Did you install Firefox "over" your previous installation, or did you remove the previous installation first? In the removal process, you have the choice to preserve or remove your personal settings. Hopefully you chose to preserve them. Could you check for multiple settings (profile) folders? Open Help > Troubleshooting Information > Show Folder Then navigate the Windows Explorer dialog up a level and see whether there are other settings folders there. Usually they have nonsense names. ''If you can see other folders,'' your previous settings might be in one of those. You could try switching from your current settings to one of the others. To do this, start up into Firefox's Profile Manager, as described in this article: [[Use the Profile Manager to create and remove Firefox profiles]]. Just select a different profile to try it and click Start Firefox. (Don't delete anything.) ''If you only have the one folder,'' can you drill down into the bookmarkbackups folder and see whether there are any older files there? These could be past copies of the bookmarks you're looking for. I think you've tried this, but if not, let us know what you find.