please go to firefox > addons > extensions & remove any suspicious entries (toolbars, things that you have not installed intentionally, don't know what purpose they serve, etc). also go to the windows control panel / programs and remove all toolbars or potentially unwanted software from there and run a full scan of your system with the security software that you have in place and different other tools like the free version of malwarebytes & adwcleaner.

Remove a toolbar that has taken over your Firefox search or home page

afterwards you can install the search reset addon - it will revert the most common customizations those adware programs do in firefox back to the default: https://addons.mozilla.org/firefox/addon/searchreset/

Thanks Philipp...the thing is that I don't see Delta installed anywhere...not on the seach engine list and not in my programs...

could you go to firefox > help > troubleshooting information, copy the contents of that page and paste them here into a reply on the forum? this might give us a clue what is going on...

delete the user.js file in your profile folder, if its there, you can check, see the link below.

• https://support.mozilla.org/en-US/kb/how-to-fix-preferences-wont-save#w_user-js-file-overriding-preferences

First, look in control panel and uninstall Browser Protect and Saveshare (or similarly named program). Then reset firefox settings manually or run adwcleaner scan. I think you have no USer.js file. There is another possibility for delta to hijack your starting page, that is changing the shortcut to firefox.