Hi blah blah, I think when you are using automatic private browsing -- also known as "Never remember history" -- the history from your non-private sessions is "read-only" and unchangeable from inside Firefox.

If you return to the normal setting, you should be able to clear that old history, then switch back.

Alternately, you could try removing the database file that stores the old history. It also stores bookmarks, but as long as Firefox has made at least one automatic backup of your bookmarks, it should be able to restore those after the file is removed.

Just in case, make a fresh backup using the steps in this article:

Restore bookmarks from backup or move them to another computer

Then, to remove the history database:

Open your current Firefox settings (AKA Firefox profile) folder using either

• "3-bar" menu button > "?" Help > Troubleshooting Information
• (menu bar) Help > Troubleshooting Information
• type or paste about:support in the address bar and press Enter

In the first table on the page, on the Profile Folder row, click the "Open Folder" button. This should launch a new window listing various files and folders in Windows/File Explorer.

Leaving that window open, switch back to Firefox and Exit, either:

• "3-bar" menu button > Exit
• (menu bar) File > Exit

Pause while Firefox finishes its cleanup, then rename places.sqlite to something like placesOLD.sqlite. If you see these files persisting after Firefox does a full shut-down, you can delete them: places.sqlite-shm or places.sqlite-wal.

Start Firefox back up again and it should rebuild the database with your bookmarks. If Firefox doesn't find your bookmarks, use the Restore feature described in the article I linked earlier.

Success?

Hi blah blah, okay, I read more carefully this time: you don't want bookmarks, either.

After renaming the places.sqlite database, also rename the bookmarkbackups folder to bookmarkbackupsOLD or if you never want to see those bookmarks again, you can delete the folder.

thank you -- it worked -- I knew the files with the history were "frozen" somewhere but know nothing about computers and dont want to know so could not find where -- you showed me where to find the files to delete the history which is now all gone and the bookmarks are still there -- so this is what I wanted to do -- thank you -- I will retain your instructions in case it happens again -- and can continue using firefox as I despise google and all the others -- thanks!