Sorry, I forgot to mention I have Windows 8.1 (yes the one where Defender is a full AV).
I didn’t manually disable Defender before running Avast Installation. Avast (probably) didn’t disable it, it just prevents the service from running (probably).
Now, all the controls in the Defender UI are greyed out, no way to get into Defender settings.
Do I need to uninstall Avast, disable Defender and re-install Avast?
How do I disable Defender properly? (aka so Windows Update won’t try to update it or it’s definitions)