User Account Control
This feature is included in the following editions of Windows Vista:
User Account Control in Windows Vista helps prevent potentially dangerous software from making changes to your computer without your explicit consent. This feature works with Windows Defender, Internet Explorer 7, and Internet Explorer 8 to help reduce the impact of viruses, spyware, and other threats. With User Account Control and the Parental Controls in Windows Vista, you can create a separate account for each member of the family and control which websites, programs, and games each person can use and install.
Manage user accounts for your PC.
Windows Vista provides two main types of user accounts, each of which will be familiar to you if you share a family PC at home or if you use a computer at the office: standard user accounts (for general users) and administrator accounts (for owners or designated administrators). You can create a separate account for every user and control which websites, programs, and games a user can use and install.
In Windows Vista, standard users are prohibited from installing most programs, changing system settings, and performing other tasks that are the province of administrators. If, as a standard user, you attempt to do something that requires administrator rights, you'll either be notified that the task is prohibited or that administrative credentials are required to proceed.
At the same time, Windows Vista extends the range of common, low-risk tasks that standard users can perform (though administrators can still choose to restrict these privileges).
Administrator privileges are essential if you are, for instance, the owner of a PC, but they can also be a liability. Online threats such as malware (including viruses and spyware) exploit administrator permissions—and they attempt to do it in secret.
Even when you use an administrator account, User Account Control provides heightened security. By default, most programs run with the permissions of a standard user, which limits the potential damage they (or malware acting through those programs) can do.
Ready to set up your computer? This paper offers specific guidelines for securing your PC running Windows Vista.