The data you are seeking is supposed to be stored in folders called "Profiles". There are a couple of things you can try to activate a profile and see/hope that it contains your missing data. If not, then there may be a chance to use an off-the-wall trick. 1) Click WIndows Start > search (or run) > FireFox.exe -p The above will execute a small profile manager and will list folders stored as profiles. There will be one that is 100% blank. And there will be another that should have your data. Try selecting/starting the other profiles listed and then re-open FF to see if it what your need it to be. The other trick involves seeing and hoping that the Win10 Microsoft Edge browser has been copying your bookmarks and passwords from FF. So open it and take a look around if it has. If so, then 2) Invoke FF's subsystem/option for the importation of data from other browsers. In this case Edge should be listed by FF and should be able to click the ok button to proceed with the import