A. The UAC feature, which strips a session of elevated privileges until the privilege is needed, drew a lot of hostile attention in early Vista beta builds. It's been refined in the final release, but some people still find it intrusive. The UAC feature can be disabled via the User Accounts Control Panel applet. Simply click "Turn User Account Control on or off," as the figureshows, and clear the "Use User Account Control (UAC) to help protect your computer" check box.
Turning off UAC is not a good idea. A better option is to use the local security settings that are available via the Microsoft Management Console (MMC) Administrative Tools snap-in. Under Local Policies, Security Options are a number of User Account Control options, which include options to automatically elevate privileges when required, as the figureshows. The setting doesn't disable UAC, but raises privileges when needed without prompting. You can configure the setting for all users or just for administrators. Additional settings exist around signed/unsigned executable behavior and installation behaviors.