That's annoying! Thank you for sharing your Firefox setup data (see Question Details > More System Details to the right of your post). That shows an optional settings file named user.js file in your profile folder (personal settings folder). Firefox uses the settings in that file at startup to override your saved preferences from the previous session. Unless you created that file yourself, it may contains instructions created by an add-on or external software to change your home page. You can check and remove the file using the steps in this article: [[How to fix preferences that won't save]]. By default, Windows hides the .js file extension. To work with files as accurately as possible, I recommend showing all extensions. These Microsoft support article has the steps: * Windows Vista and later: [http://windows.microsoft.com/en-us/windows/show-hide-file-name-extensions] * Windows XP: [https://support.microsoft.com/en-us/kb/865219] If you delete or rename the user.js file and then close and start Firefox again, does your home page remain undisturbed?