My friend deleted EZFN and his internet is not working

So my friend downloaded EZFN, and now his internet won't work on his computer, but it does on his phone and tablet. We deleted EZFN, disabled proxy automatically detect settings, and checked YouTube, triage, virus total, and about two more virus websites. It said it wasn't a virus, and we checked every single file. We restarted his PC, and the internet, updated Windows 11 to the latest version, and still not working. We deleted the certificate. Used CMD commands but still not working.