I have Avast Premiere and updated it this morning. When the system rebooted, the firewall would not start.
The fix was to go to the Uninstall in the Control Panel -- there is an option to REPAIR.
I did this myself. IT was easy.
However, before I did it, I called Avast Support and spent 30 minutes with "Anne" telling me I needed to pay Avast $180 to have a "technician clean my computer."
She tried to tell me that Windows was corrupted and there were a "bunch of errors" in my system. Never mind that the Microsoft Reliability graph showed 9-10 every day for the last few months. She also said the problem was likely due to another antivirus -- I installed Avast when I built the system. It's never had anything else.
It was a complete waste of my time to call -- and she didn't even go directly to the REPAIR option, which should have been her first stop.
If you have an issue, go to Uninstall in Control Panel and it will let you do the Repair option. Don't waste your time being told you need to spend $180 to have a "technician clean your computer."