You can look at the browser.newtab.url pref on the about:config page and set that pref to the URL of your preferred new tab page. You can use these special pages or set the pref to the URL of your preferred new tab page.

• the default new tab page with the tiles is about:newtab
• the default home page is about:home
• for a blank page you can use about:blank

The browser.newtabpage.enabled pref should be set to true to use the page set via browser.newtab.url as the new tab page.

You can open the about:config page via the location/address bar. You can accept the warning and click "I'll be careful" to continue.

• http://kb.mozillazine.org/about:config

Tried it. The change stuck but didn't work and it changed my homepage again.

Do you keep the browser.newtab.url pref during the current Firefox session?

Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem.

• Switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance
• Do NOT click the Reset button on the Safe Mode start window

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

If it works in Safe Mode and in normal mode with all extensions (Firefox/Tools > Add-ons > Extensions) disabled then try to find which extension is causing it by enabling one extension at a time until the problem reappears.

Close and restart Firefox after each change via "3-bar" menu button > Exit (Power button) (Windows: File > Exit; Mac: Firefox > Quit Firefox; Linux: File > Quit)

There is software like Advanced SystemCare with its Surfing Protection feature that can protect files in the Firefox profile folder against changes. If you have such software then check the settings or uninstall this software.

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

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