I always thought that was true until I tried to add additional accounts with
Administrator privilege. The new accounts do not have the Admin privilege.
The only one that does is the original account I set up the first time the
new computer was booted (2 years ago).  I've deleted the new accounts and
created them again many times but still the same problem.

Basically what it is saying is only one admin account, other than the system
account, is allowed.

Frank