Okay got Avast installed with an offline updater, and now I can't update the vir

us definitions, it says there is a connection but when I hit update it tries for a few seconds and goes to unknown error. My Comodo Firewall isn’t blocking anything to my knowledge since I tried disabling it and updating and I got the same error.

Tried doing a repair and even that didn’t help.

Remove Comodo and check if the problem is solved.

I uninstalled Comodo and I still get an error message.

I have same problem as OP. Unintalled Avast Free (in safe mode), uninstalled Comodo clear all traces of both programs.
Attempt 1. Online installer (Windows firewall turned off, Router firewall disabled) ended with erorr message not installed, conection to avast servers not established (no traffic in task manager jus few peaks with maximum 8 kb/s)
Attempt 2 Online installer (Windows firewall turned on, Router firewall disabled) same results
Attempt 3 Offline installer (Windows firewall turned on, Router firewall disabled) Avast installed, can not update VPS nor program it self via emergency updater. Connection can not be eatablished. One more weird thing. It is not needed to restart my PC after installing Avast in all cases. As observed Avast installer process hangs for quite long time in task manger. Updating VPS always returns unknown erorr.
Note: Log send to support.
Unforunatelly after 5+ years I am back on Win Defender.
Jack

I thing that I have found solution for those troubles. It works for those who have Atheros Killer exxxx Gigabit ethernet controlers. Just disable Killer Bandwith Control within network properties. Perform emergency update reboot and you are set. Jack