Windows Genuine Advantage, developed by Microsoft, is a system that discourages piracy by enforcing the online validation of Windows operating systems. Also known in its shortened form WGA and Windows Activation Technologies (in Windows 7), it is activated when users access Microsoft services such as Windows Update and when Windows components are downloaded from the Microsoft Download Center.
WGA is made up of two components: WGA Notifications and an ActiveX control.
WGA Notifications – is linked with Winlogon and functions to validate the computer’s Windows license every time the user logs on. It covers the operating systems Windows XP, Windows 7, Windows Vista, and Windows 8. ActiveX – verifies the validity of the license when updates are downloaded. In addition to the operating systems covered by WGA, it also checks and verifies Windows 2000 Professional licenses.
If Windows Genuine Advantage detects that the Windows operating system does not have a valid license, it shows a notice and prevents the system from downloading non-critical updates and components. It will require the user to purchase a new copy with a valid license. Critical security updates may still be downloaded through the Microsoft Download Center.
Upon installation of the WGA, a browser (Internet Explorer) add-on is also installed, labeled with the application’s name. To check and verify updates, it requires connection to the Internet. The application also comes with a WGA Validation Library, which helps in checking for license key overuse.