Hi, try this: Type about:config into the address bar, press Enter, accept the warning, scroll down to browser.newtab.url and make sure 'Value' is set to about:newtab (right click to change it if necessary, taking care not to alter anything else).

If your question is resolved by this or another answer, please take a minute to let us know. Thank you.

Here are some potential diagnoses and remedies when you run into problems with that setting:

If Firefox won't let you edit this setting in about:config: you may have something called SearchProtect on your system. This needs to be removed from the Windows Control Panel.

If Firefox lets you save your change but ignores it: one of your extensions may be overriding it. You can review, disable, and/or remove extensions on the add-ons page. Either:

• Ctrl+Shift+a
• "3-bar" menu button (or Tools menu) > Add-ons

In the left column, click Extensions. Then cast a critical eye over the list on the right and disable (or remove) anything unknown.

If the change works during your session, but at the next startup is back to the unwanted page: you might have a user.js file in your personal Firefox settings folder (your Firefox profile folder). This article describes how to track down and remove the file: How to fix preferences that won't save. Also, Advanced SystemCare can cause this.

Any luck?

You can check for recently installed suspicious or unknown extensions.

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