Defender is still in W10? News to me! I haven't seen hide nor hair of it in the year I've been running W10...
Ok, I've seen definitions updates for it in win update, but I assumed they removed the GUI and just made it like a system service that runs silently in the background...
Defender is the most silent Antivirus ever. It never nags you unless something really bad happened.
Normally it just silently murder the viruses. Kidnap them to Microsoft HQ (if you allow it to do kidnapping). Etc.