Hi Nayakpr2, the Firefox 58 (or Firefox 60) installer should find and update your Firefox settings files. Sometimes the installer will suggest or perform a Refresh if you haven't updated for a long time. Check the computer's desktop for an Old Firefox Data folder. Firefox creates regular bookmark backups you could use to restore bookmarks. See: [[Restore bookmarks from backup or move them to another computer]]. Occasionally the Places database that stores bookmarks and history becomes unreadable in a different version of Firefox due to an imperfection in the data structure. In that case, you might need to rebuild the database using the method in this article: [[Fix "The bookmarks and history system will not be functional" error message]]. Some people would suggest not upgrading in such a large step all at once. Instead, you could install intermediate versions such as Firefox 45 and Firefox 52, before Firefox 60. I don't have enough data to know if that makes a real difference. (Old installers: [[Install an older version of Firefox]])