Hello,
In Windows Vista, even though you are an administrator, only programs that
explicitly ask for your permission ("Windows needs your permission to
continue") or programs that you explicitly grant permission are allowed to
have admin access to the computer.
Programs that do not ask for permission or that you do not give access,
cannot use your administrator powers.
To manually give admin access to a program that does not ask for permission,
right-click it and click Run As Administrator.
You will need to do this for command prompts that you wish to run
administrator prompts from, as well as the version of the nvidia control
panel that you have, it seems.
Updating the software on your computer when they are made vista-compatible
should help with this problem, as Vista-compliant applications will prompt
you for permission when it is needed.
--
- JB
Microsoft MVP - Windows Shell/User
Windows Vista Support Faq
http://www.jimmah.com/vista/