Open a new window or tab. In the address bar, type about:config. If a warning screen comes up, press the Be Careful button. This is where Firefox finds information it needs to run. At the top of the screen is a search bar. Enter browser.newtab.url and press enter. browser.newtab.url tells Firefox what to show when a new tab is opened. If you want, right click and select Modify. You can change the setting to;

about:home (Firefox default home page), about:newtab (shows the sites most visited), about:blank (a blank page),

or you can enter any web page or about: page you want.

The same instructions are used for the new window setting, listed as browser.startup.homepage.

Your System Details list shows that you have a user.js file in the profile folder to initialize prefs each time Firefox starts.

The user.js file is only present if you or other software has created this file and normally it wouldn't be there. You can check its content with a plain text editor (right-click: Open with) if you didn't create this file yourself.

The user.js file is read each time Firefox is started and initializes preferences to the value specified in this file, so preferences set via user.js can only be changed temporarily for the current session.

If you do not keep changes after a restart or otherwise have problems with preferences, see:

• http://kb.mozillazine.org/Preferences_not_saved

I have this problem, too. In the past, I had no problem setting the new-tab default to my preferred site. Firefox recently did an automatic update and when I went to open the browser again, my default homepage and my default new-tab was changed to firefox's default. I have been able to easily set my homepage to my preferred site, but the new-tab option wont work. I go to about:config then to browse.newtab.url and change it to google.com. In the past, I had no problem having this preference stick, but now it only stays till the close and re-open Firefox the next time. At this time, it gets set back to firefox's default. I have Firefox 33.1 and the site tells me this is the latest version. Any suggestions for how I can make the new-tab page stay set to my preference even after closing and re-starting the browser?

Hi Snaily, could you check this article: How to fix preferences that won't save.

Also, if you use Advanced SystemCare, it has a feature to block changes to browser settings that works by rolling back your settings when you exit Firefox. Other privacy/utility programs may have similar settings protection features.