That Delta toolbar is one very annoying hijack toolbar. It hijack’s your default search engine, and people absolutely hate it. First and foremost, I would recommend you try Malwarebytes to remove this annoyance. 2nd I would try uninstalling any unknown or suspicious apps from your Windows programs manager. Consider using a safer browser like Chrome, and also make sure you uninstall Delta toolbar or any suspicious extensions from Chromes or Firefox extension manager. If you click settings you should see an option to get to the extensions screen. If all of this doesn’t work, and you really wish to get this annoyance out of your system. You should consider a complete factory system restore. Most newer computers come with the feature ,where you press certain keyboard keys when booting up your laptop or desktop PC’s.