The browser.preferences.inContent is no longer supported in Firefox 42 and later, so it is not possible to open a standalone window.

• bug 1140495 - Remove support for windowed preferences

Please do not comment in bug reports
https://bugzilla.mozilla.org/page.cgi?id=etiquette.html

When 'The browser.preferences.inContent is no longer supported in Firefox 42' became? In 43?

czeslawa: You're asking if that feature will no longer be supported beginning with Firefox 43 -- Is this right?

My understanding of cor-el's answer is that the workaround has already been discontinued in the current version, Firefox 42. This is consistent with my experience. browser.preferences.inContent still exists in about:config, but can no longer be set to view Tools|Options in a pop-up window instead of a new tab.

You will only see browser.preferences.inContent on the about:config page if you have previously toggled this pref. You can right-click a no longer supported pref like this one and "Reset" the pref to have it removed from about:config on the next Firefox start.

So how open oprions in window, not in tab? Tab is awful and unconfortable!

The browser.preferences.inContent is no longer supported in Firefox 42 and later (bug 1140495), so it is not possible to open a standalone window by setting this pref to false.

You can possibly create a button on the Bookmarks Toolbar to the about:preferences page and hold the Shift key and left-click to open the page in a new window.

You can look at the Classic Theme Restorer extension.

• General UI (1): Open options page (about:preferences) in a window

If that isn't working or the choice is missing then you might be using a theme that isn't supported. You can check that by switching to the default theme.

I know, its great extension that make firefox usable but the window dont look like it was, I want to see the old style window exactly as it was.

The CTR extension only opens the Options/Preferences page in a standalone window instead of in a new tab and makes some CSS changes to show the sidebar as a bar at the top. Restoring the appearance to its previous state isn't possible as that would be impossible to achieve and maintain across versions.

I stayed on an older version of firefox until today to avoid these exact sort of "improvements" that just make it more difficult to use firefox. I typically have a lot of tabs. "options" opening in a new tab at the bottom of all the tabs I already have is a royal pain, because I have to navigate to it, and then when I'm done, find my way back to the tab I was on before I started. I REALLY want it to open in a new window again too.

How about giving us that option, Mozilla? Let it be a setting in the "advanced" tab of the options menu or something that way.

I also hate the new location of the menu icon. When it was the orange button in the upper left hand corner, that freed up some space on the crowded toolbar that already has the website address box, search box, and a bunch of my add on icons on it - while the title bar sits there totally empty wasting precious vertical space on my laptop screen, when all that's on is is the three tiny icons/buttons on the right for minimizing, closing, etc. How about letting us put icons on the title bar too??

You can consider to open the about:preferences as a pinned tab or open the page permanently in a separate window for easy access if you use this page quite often.

I'm using Firefox 43.0.1 and this worked for me.

- Launch Classic Theme Restorer (I use version 1.4.5) - Select Options page, then choose either

Open options page in a window or Open options page in a window (v2)

- Press OK and that is it. Options pop-up window works again.

After reading this as I am also using FF 43.0.1 at home, I installed the add-on classic theme restorer and happy that I now have the Options open up in a window.

At work, I still use 39 and will not be updating it since I found out at home the Mozilla developers had removed the windowed option from 42 onwards.

Still prefer if Mozilla kept that choice whether to turn the Prefs to open up in window or tab and not having to use an Add-on to do this. For me, TABS are for browsing the internet, not for settings. I don't like using Google Chrome because of the tabbed Prefs. And just like anonymoose, I too have a lot of tabs opened. (FFS Mozilla)

I am sure there are many people like myself and anonymouse who do not like this "new improvement". If there is a petition around to sign to get the Mozilla developers to bring back the windowed prefs, I will sign it in a heartbeat. Or I might create the petition myself and/or maybe a youtube video leading to the petition as youtube tends to be receive faster response than a petition by itself :)

Seriously??? I can't get rid of the stupid new tab now?!?!?!?!? I neither want nor need the browser settings to work on anything but a desktop, and I resent that I can't have the options I always liked. If this nonsense continues, I swear, I might switch to Chrome. Come on Firefox, this is unacceptable. Some of us, a lot of us, still use computers.

The browser.newtab.url pref is no longer supported in Firefox (41+), so it is no longer possible to set the new tab page via this pref.

You can look at this extension to set the new tab page:

• New Tab Override: https://addons.mozilla.org/firefox/addon/new-tab-override/

You can set the new tab URL via the Options/Preferences of the extension on the about:addons page.

You can look at this extension if you use the home page as the new tab page.

• New Tab Homepage: https://addons.mozilla.org/firefox/addon/new-tab-homepage/

Classic Theme Restorer includes this feature as well. You find "New tab page url" in the Tabs (2) section.

You can use pages like these:

• the default new tab page with the tiles is about:newtab
• the default home page is about:home
• for a blank page use about:blank
• for Super Start use about:superstart
• use the URL of a web page

See the about:about page for available about pages.