Go to Options -> Home -> Firefox Home Content -> uncheck Top Sites

Thank you for the help. I don't think I made myself under stood very well. I want to keep the 6 Top Sites I have but do not want FireFox to add any when I go to a new web site. I want to be able to add the ones I want myself. As it is now FireFox keeps adding any site I open up. CK

Hello buckboy,

When you pin the tiles that you want to keep, Firefox won't be able to change them. However, if you have some 'empty' tiles, then sites you visit will be added - to stop that behavior, you could edit those tiles and enter the URL of a site that you don't mind seeing on the new tab page (and then pin them). You can always edit them again later.

See : https://support.mozilla.org/en-US/kb/customize-new-tab-page

'Hope that will work for you .....