Thanks, rdmaloyjr. I'm getting mixed signals here. Maybe my fault for not making myself clear. I'm using both ZAPro (firewall) and Avast Pro (antivirus) now, both paid programs.
If I have to uninstall Avast, how do I re-install without losing my current subscription. So guess I'm back to my original question. (At this point, I'm tempted to dump one or the other if it's complicated.)