Enable the (Hidden) Administrator Account on Windows Vista
 

Many people familiar with prior versions of Windows are curious what happened to the built-in Administrator account that was always created by default. Does this account still exist, and how can you access it?

The account is created in Windows Vista, but since it's not enabled you can't use it. If you are troubleshooting something that needs to run as administrator, you can enable it with a simple command.

http://www.howtogeek.com/howto/windo...windows-vista/

Turning off UAC under the User Accounts menu basically defaults the user as an Administrator... CMD prompt windows are automatically granted Admin privileges and other menus assume the same privilege level.

for your own machine I agree, for machine for relatives, friends or other IT challenged people, it can be good to have an account to fall back on to do the installs and a "user" which can do nothing but "use" the machine and the applications