Thanks for the suggestions. 

The first suggestion resulted in one response "audit mode enabled" or something to that effect.  Rebooted, but Norton_Removal_Tool won't do anything (click setup, then it just sits there idle), and setup.exe still won't do anything apart from a brief hourglass.

Next I downloaded SymLMTS.exe.  Brief hourglass, then nothing.  No window, no on-screen instructions ... nothing.