hi Blackceed, firefox doesn't support group policy settings - the best way to go about deploying some settings across a large number of devices or locking settings so they cannot be changed is probably the way described in http://kb.mozillazine.org/Locking_preferences which basically consists of dropping two files into the firefox program folder...

yes I already knew about the link that you provided me regarding the policy but I need to find the appropriate settings to restrict or disable it from the "about:config" window; then it will be easier for me to modify the appropriate config file.

Thank you for your prompt response

unfortunately i cannot enlarge your second attached image so i cannot see which exact configuration you're looking for... could you describe it in words?

Is the about:privatebrowsing page showing in the screenshot?

In what way do you want to restrict private browsing mode?

Restrict the Privacy Browse menu to not allow modifying the "Tracking" default option ( tell sites that I do not want to be tracked).

I want to make sure we cannot modify the Tracking config so it’s set to “Do not tell sites anything about my tracking preferences" (as per screenshot below)...I know there is a way to do it through the "about:config" settings.

Note that the do not track setting only makes Firefox adding a DNT=1 to the HTTP request headers.

• https://www.mozilla.org/en-US/firefox/dnt/

This has been changed to of/off state and is no longer a three-state setting in current Firefox releases (i.e. privacy.donottrackheader.value is no longer supported).

• bug 1042135 - Revert do not track preferences to be a simple on/off switch (privacy.donottrackheader.enabled)

This code in the mozilla.cfg file should be sufficient to ensure that the value is locked to a false state.

//
lockPref("privacy.donottrackheader.enabled", false);

You can use a mozilla.cfg file in the Firefox program folder to lock prefs or specify new (default) values.

Place a local-settings.js file in the defaults\pref folder where also the channel-prefs.js file is located to specify using mozilla.cfg.

pref("general.config.filename", "mozilla.cfg");
pref("general.config.obscure_value", 0);

These functions among others can be used in the mozilla.cfg file:

defaultPref();	// set new default value
pref();		// set pref, allow changes in current session
lockPref();	// lock pref, disallow changes

See:

• http://kb.mozillazine.org/Locking_preferences
• http://mike.kaply.com/2012/03/16/customizing-firefox-autoconfig-files/

that's exactly what I needed and it's working with the previous Mozilla Firefox browser.... We will probably upgrade our current version to the newest one in the near future throughout the organization. Thanks a lot for all the info and tips you provided.