grampymunn, you may be able to find bookmark backup files on your hard drive, but note that before searching you may need to enable the viewing of hidden files and folders first. Sometimes after a Windows version change or rreset, old user data can be moved to a "C:\Windows.old" folder on the hard drive. You could try searching this folder (if it exists) for bookmark backup files. If nothing is found here then you could try searching the whole of your hard drives. Firefox maintains backups of bookmarks in a folder named "bookmarkbackups" within a profile folder. So you could try searching for folders with this name. The backups will have names of the form "bookmarks-*.jsonlz4". So alternatively you could try searching for filenames matching this pattern instead. The filenames should include a date, so it will be easy to tell which are the most recent backups. If you find a backup file then you can import it via the "Import and Backup" menu in the bookmarks library. See the "Restoring from backups" section here: https://support.mozilla.org/en-US/kb/restore-bookmarks-from-backup-or-move-them (But note the part "Caution: Restoring bookmarks from a backup will overwrite your current set of bookmarks with the ones in the backup file". So you may wish to note or export any pre-existing bookmarks first.)