Hi

I have had a look into this and asked some fellow contributors that have advised two options (both with the same result):

Type about:preferences#privacy into the address bar and change the setting under History so that it reads that Firefox Never remember history.

or

1. Type about:config in the address bar and search for browser.privatebrowsing.autostart.
2. Double click on the setting and set it to True

I hope this helps, but if not, please come back here and we can look into a different solution for you.

You can also use a command line switch to open Firefox in Private Browsing mode (-private-window).

• https://developer.mozilla.org/Command_Line_Options