See:

• https://support.mozilla.org/kb/new-tab-page-show-hide-and-customize-top-sites

The URL of the new tab page is about:newtab

The URL of the build-in home page is about:home.

If there is a problem with the build-in about:home page then try to reset the search engine used on the about:home page.

Reset the browser.startup.homepage_override.mstone pref via the right-click context menu to the default on the about:config page and close and restart Firefox to restore the about:home page to its default.

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

1. Open the about:config page via the location bar
2. Type in the Filter bar: mstone
3. Right-click the browser.startup.homepage_override.mstone line and select: Reset
4. Close and restart Firefox

If this didn't help then delete the delete the chromeappsstore.sqlite file in the Firefox Profile Folder and repeat the above.

Newtab! Thank you! I suspected....

Few simple, and sure to work steps!

1. Open another Firefox tab.
2. on the URL, type about:config
3. Promise to be careful
4. Next to the Search bar is your blinking cursor; type in browser.newtab
5. Click on the highlighted search result which should be browser.newtab.url
6. Double-click and change it to what you want like: <spam link removed by moderator>
7. Smile and thank that you can read. ^_^

Thanks so much, it worked! <3