I got no idea why this is happening, if this is Avast related or not. I know AIS firewall isn't supposed to turn off Windows firewall, and it doesn't. So to make sure I just turned off AIS firewall, turned Windows firewall back on, and rebooted >>> windows firewall is de-activated again. And this is reproducible. No idea if it's the firewall driver from Avast that conflicts and does this... any clue?
Also, I noticed that the homegroup tab in explorer left panel doesn't display other computers anymore, although my system joined a homegroup, and I can see (in the Network folder) and access network shared folders on another system that is part of the LAN.
using: 5.1.874