Hello,
In Windows Vista, if you are NOT connected to a domain, the built-in
Administrator account is completely disabled unless it is the only
Administrator account that is available to be logged in to; in that case,
the system SHOULD allow you to log in to it from safe mode only.
If you ARE connected to a domain, the built-in administrator account is
ALWAYS disabled - you will need to log in to your computer with a
domain-level administrator account.
If you are not connected to a domain, and there are no other administrative
user accounts on your computer that are available to log in to, and Windows
will not let you log in as the built-in administrator in safe mode, then
this is improper behavior and should be bugged.
--
- JB
Windows Vista Support Faq
http://www.jimmah.com/vista/