Which Windows Vista security feature prompts before elevated admin actions?

User Account Control, or UAC, is the Windows Vista security feature that prompts before actions requiring elevated administrator privileges. It was designed to prevent programs from silently making system-wide changes.

Even users in the Administrators group normally ran applications with standard-user permissions. When an installer or system setting needed higher privileges, UAC displayed a consent prompt; standard users could instead be asked for administrator credentials. The prompt could appear on Windows' Secure Desktop, temporarily dimming the rest of the screen.

UAC is not the same as Windows Defender, SmartScreen, or BitLocker. Defender focuses on malware protection, SmartScreen helps identify unsafe content, and BitLocker encrypts drives. UAC primarily controls privilege elevation, reducing the damage that unwanted or malicious software can cause.