hi, this is currently a bug when you clear certain parts of your history on shutdown - a fix for this will ship with firefox 45.

Meanwhile, to try to ensure Firefox completes the job of clearing history at shutdown, it's best to exit from the menu, either:

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

If you typically close Firefox using the "red X button" on the title bar or other methods where Windows may kill Firefox prematurely, please give that a try and see whether it makes any difference.

Thank you both for replying.

Yep try'ed that; "3-bar" menu button > "power" button

   (menu bar) File > Exit " No joy!

When will ff45 be out?

you could try it out in beta right now: www.mozilla.org/beta the general release is scheduled in 2 weeks time, but i'm not sure if this date will hold, since there are some stability issues still, which will need to be ironed out before that...