This particular product likes to do a clean install rather then an upgrade. I un-installed the old product but for some reason one file was missed. The result was that the new firewall installed but did not complete. It came up in default status - blocking all access to the net - but could not be reconfigured.
The solution was frankly a royal pain. The entire package had to be uninstalled. To make sure I used both Window's uninstaller and then a commercial product. [... and it did find things that Windows had missed.] Neither program properly cleaned the Registry, so it was necessary to use regedit and do a line by line search, deleting all references to the prior installation.
After all of this, the machine was still in a locked down status. At this point I reinstalled everything and this time it "took" and allowed me to configure.
I know that by their nature. virus scans and firewalls must operate "deep" but I really wish that this one had been a bit more user friendly. [I will omit the product name to protect the guilty.]