period in which to then pass validation, after which most of the operating system is disabled and Windows reverts to reduced functionality mode. This behavior however has been removed in Service Pack 1 of Windows Vista in favor of prominent notices on systems believed unlicensed. Software WGA Validation Tool When a user installs Windows Genuine Advantage, an Internet Explorer add-on is installed labeled "Windows Genuine Advantage". In early releases the tool could be readily disabled with the IE Add-on Management feature. A Windows Group Policy was added by later updates, causing this option to be unavailable by default, but still accessible if the policy were removed. As of July 2006, the latest update blocks management by other means. The program uses either a stand-alone program to generate a key or an ActiveX control to discover whether the license key is valid; either way an Internet connection is required. On Windows XP, 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. However, newer versions of Windows will still require the user to purchase a new copy. Microsoft also offers discounts to people who want to purchase a legitimate copy of Windows but do not have a valid CD. Microsoft has indicated that they will continue to deliver critical security updates through their Automatic Updates service as well as via the Microsoft Download Center, so that all systems, including those that fail to pass validation, will still continue to receive critical security updates. The company has made installation of Windows Genuine Advantage a requirement for use of the Windows Update and Microsoft Update websites, in part to be sure that customers who use support resources of the company are aware when their software is unlicensed. According to Microsoft themselves, it is legal to run Microsoft Windows without Windows Genuine Advantage . 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. WGA Notifications On April 25, 2006, Microsoft began distributing Windows Genuine Advantage Notifications as "critical update" KB905474 to Windows users. For Windows 7, KB971033 has the same function. Back in 2006, users with copies