I fixed this issue.
After trying to get rid of Avast and failing because my internet was not working, I tried to "repair" Avast, which also failed. But, I was able to turn off all the "components" of Avast.
Looking at services, I saw that many of the services had been disabled. Not exactly sure how or why that happened. I could not figure out a way to enable them en masse. So I used this list by blackviper to figure out what all the defaults should be:
http://www.blackviper.com/service-configurations/black-vipers-windows-10-service-configurations/ It was painful but I got it done.
A reboot after the changes to services seemed to fix things - sort of. The internet would not come up but at least it recognized there was an adapter. The windows trouble shooter could not fix it. Looking at adapter properties, there were a ton of "items" it could use to set up the connection. I unchecked most of them, leaving only these checked on: ipv4, ipv6, qos pkt scheduler, and two related to link-layer topology. That seemed to fix the internet.
Once the internet connection was back on, I was then able to to use avastclear.exe to get rid of Avast completely. After another reboot, I reinstalled Avast. I turned off the "behavior shield" component.
Once Avast was installed and survived a reboot, I installed Comodo. As far as I know I only have the firewall turned on. I need to still figure out how to silence the annoying geekbuddy popups. But that can wait.
A couple of more reboots later, everything seems to be working. I noticed that Comodo has added itself to the Ethernet adapter properties as one of the protocols (in addition to the ones I mentioned above).
I created a system restore point, just in case.
Here is to hoping the computer stays operational !