Comparing Windows 7 with UAC to Windows XP Behavior

Users of both Windows XP and Windows 7 may still find it difficult to understand the behaviour of User Account Control (UAC) mechanism used in Windows 7. UAC is a security feature of Windows 7 that informs you when the action that you want to take to undertake requires an elevation of privileges. The list below explains the behavior changes in Windows 7 with UAC enabled when compared to Windows XP.

Windows XP

Windows 7

User is logged in as a standard user but can run administrative tools by right-clicking the tool’s icon, clicking Run As and then providing administrative credentials. User is logged in as a standard user but UAC immediately prompts the user for administrative credentials when he/she opens administrative tools or applications that require elevated privileges.
Application fails to modify a system setting if user is logged on as a standard user. UAC provides virtualization for important parts of the system, allowing the application to run successfully when a user is logged on as a standard user.
If a specific feature within an application required administrative privileges then the entire application required administrative privileges. Windows 7 displays the UAC shield on buttons to warn users that the application or a feature requires elevated privileges.
User is logged on as an administrator, therefore all applications ran with administrative privileges. Although user is logged on as an administrator, all applications run with standard user privileges. However, Windows features that require administrative privileges automatically receive elevated privileges but any non-Windows applications that require elevated privileges, Windows 7 displays a UAC prompt to inform the user.

Read more about UAC here –