Antivirus: yay or nay?

[Beskar]

I tried it and got BSODs.

I was able to recover it by booting repair mode, getting a command prompt and using bcdedit to remove the entries that were modified by msconfig. I don't doubt that it worked good on your system, but I post this as a cautionary note to others who might make the changes. Depending on your setup, it could improve things, but it's not without risk*.

Spoiler Alert, click show to read: 

Risk that I should have recognized, but didn't. So it served as a good reminder on my part

The BSODs might be related to hardware issues on your end or needing to update drivers. You would experience the same issues if you were running a game or so.. because all it is doing is giving permission to use all your cores/memory on boot-up.