Restored computer

I recently restored my computer to the factory settings and had a question about the order in which I should do things.
-Should I keep Norton on my computer until Windows has finished updating? The reason I ask is cause I have had issues when I have used to Avast and Online Armor during the Windows update. And have been told you should never be connected to the internet w/o a firewall or AV.
-What malware scanners would most be recommended?
I have been using Windows defender, malware bytes and Spybot Search and Destroy.