Are you always getting redirected to stopnotifications.com when you open your homepage? If this is the case, a browser hijacker is causing this. Stop Notifications will attempt to commandeer your default browser and search results from this fake search engine will send you to malicious websites to get money from you or infect your computer further. It may also prevent you from changing your settings back.
Stop Notifications is usually installed through bundled software without you knowing. Remove it immediately.