The WGA validation process validates the present installation of Windows and its license key against the detected computer hardware and determines if the software was licensed from Microsoft.It is accessible by either a stand-alone program, a Netscape-compatible web browser plug-in, or as an Active X control within Internet Explorer, the latter of which is relevant to any attempt to access Microsoft updates via its browser.
It ensures your Windows license key is only being used on a single PC at a time and that thousands of PCs aren’t using the same key.
Windows Genuine Advantage (WGA) is an anti-infringement system created by Microsoft that enforces online validation of the licensing of several recent Microsoft Windows operating systems when accessing several services, such as Windows Update, and downloading Windows components from the Microsoft Download Center.
In Windows 7, WGA is renamed Windows Activation Technologies.
In an April 16 Windows Secrets story, contributing editor Ryan Russell argued that WGA poses a risk to the world because Microsoft prevents machines that fail WGA validation from getting some security patches through Windows’ Automatic Updates mechanism.
Unpatched machines are vulnerable to remote attacks that enroll them in hackers’ bot armies.