There are at least three possible reasons for this: (1) An add-on is changing your home page at startup. You can review your extensions for possible miscreants 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, if in doubt, disable. Often a link will appear above at least one disabled extension to restart Firefox. You can complete your work on the tab and click one of the links as the last step. Does that stop the changes? (2) An optional settings file named '''user.js''' is overriding your change at startup, or there is another problem with updating your preferences. Please see this article for more information: [[How to fix preferences that won't save]]. (3) A utility program like Advanced SystemCare is rolling back your changes between Firefox sessions. In addition to ASC, some other security/utility software has a "home page protection" or "browser protection" feature that can do this. Do any of those help?