Administrator

From Support

In Microsoft Windows, an account is created that has all authority on the local machine. This account is typically called Administrator, although other accounts with the same authority may be created.

To run a program as a local administrator in Windows Explorer, click the program executable file that you want to open. Press SHIFT and hold, right-click the program icon, and then click Run as. To log on using an Administrator account, click The following user. In User name and Password, type the Administrator account name and password that you want to use.

MAKE TRUE REFERENCE Source: Windows XP Professional Help & Support Center.

See Microsoft for more information on user authority.