Since Avast wouldn't start from the desktop icon, I used Control Panel to Repair the installation. After a restart, Avast is now working. But in the Firewall settings the "Show notifications for automatic profile switching" box is unchecked. Even so, it pops up several times a day to let me know that it has found a new network, and set it to Private. This seems to be a glitch. I have manually set all networks to private, even though they are connected to the public internet. Any other ideas?