You're not infected with anything. All you're seeing is a scary webpage that keeps reappearing - probably because Edge has been set to re-open "previous pages" every time it's launched. Try this:
Make sure Edge has been closed (use Task Manager if you can't do it the normal way) then disconnect your computer's Internet connection. Re-open Edge and hopefully that page will be unable to load and you can then close its tab. If it does reappear then press the CTRL+F5 keys to refresh the page.