What is the difference between WGA Validation Tool and WGA Notifications?
WGA Validation determines whether the copy of Windows XP installed on a PC is genuine and licensed. WGA Validation was launched worldwide in July 2005. It is required for any download on Windows Update, Microsoft Update and the Download Center. WGA Notifications is software that is distributed through Automatic Updates that reminds users who fail validation that they are not running genuine Windows and directs them to resources to learn more about the benefits of using genuine Windows software. WGA Notifications is currently not required to use Automatic Updates.