If I switch to Admininistrator from Default User and open explorer I get a
pop-up dialog
Validation failed for

VSINIT.DLL ...(several files)
You are probably missing the necessary root certificates

Windows would not let me run SFC /scannow from Administrator but I switched
back into default user and ran it. However the problem is not fixed.

Searching the System disk reveals that VSINIT.DLL exists as on version in
windows\System32 and a newer version In the ZoneAlarm Folder.

Any thing else I can do? I do not want to undertake a heroic repair install
as the system runs perfectly in normal user mode.

Uncle John