A couple of weeks later, after connecting with a wireless network "out there", it happened again. This time uninstalling Comodo was not enough. It's gone for good. I now have the Windows firewall and Avast AV. And no network connection.
After trying a long list of fixes, I have determined that the hardware is fine, the connection is there and alive -- pings work, and the Network Connections window lists it as "Connected, Firewalled".
I just deleted all twelve keys from the Registry that include the term Comodo. That regained connection with the laptops own Shared Docs folder, but it still won't connect with other computers. This is progress, but not success.
It is now clear to me that Dragon Doodoo is the problem, and that many pats are still there. Does anyone have a clue where else I should look to clean out the rest?