I use Win XP Home, SP2 with all the critical updates current on a laptop
computer. My user account (the only account that is present on the system) is
an Administrator account. Lately, when I launch the MSCONFIG system
configuration utility to do a selective startup or a diagnostic startup, I
receive an error message that says "An access error message was returned
while trying to change a service. You may need to log on using an
Administrator account to  make the specified changes."

How do I fix that, since I am using an Administrator account when I recieve
the error message?