Hi there. I accidentally downloaded an app "startfenster.de" when updating VLC player. I deleted the app from my laptop but the website still opens whenever I start firefox. I tried changing the settings for the Browser, cleaning the cache, rebooting the laptop but nothing works. What can I do? The website https://www.startfenster.de/ doesn't seem to be dangerous but I still fnid it rather annoying. Thank you for your help! Katrin