However, since non-critical Windows updates are not presented by Automatic Updates, installation of WGA is required for installation of such non-critical updates, which are only available through Windows Update or the Microsoft Download Center.
It was updated again on May 30, June 6 and June 27, 2006, though some forms of circumvention are still usable.
WGA also advertises the latest service pack, Service Pack 3, for Windows XP, which requires manual intervention to disable.
In Windows 7, WGA is renamed Windows Activation Technologies.
WGA consists of two components: an installable component called WGA Notifications that hooks into Winlogon and validates the Windows license upon each logon and an Active X control that checks the validity of the Windows license when downloading certain updates from the Microsoft Download Center or Windows Update.
The program uses either a stand-alone program to generate a key or an Active X control to discover whether the license key is valid; either way an Internet connection is required.
If WGA determines that a user's copy of Windows is unauthorized but was installed from seemingly legitimate media (i.e., the CD/DVD and holographic emblem present on real copies of Windows seems genuine), then Microsoft will supply the user with a new CD/DVD. Newer versions of Windows will still require the user to purchase a new copy.
WGA Notifications covers Windows XP and later, with the exception of Windows Server 2003 and Windows XP Professional x64 Edition.