Vista, XP, 2000, Server 2003 Working Activation Key

Features

The WGA validation process validates the present installation of Windows and its license key against the hardware involved. It is accessible by either a stand-alone program, or as an ActiveX control within Internet Explorer, the latter of which is relevant to any attempt to access Microsoft updates via its browser. It includes the following steps:

Upon their first visit to the Microsoft Download or Update Center, the users receive a message requiring them to validate their copy of Windows by downloading an ActiveX control which checks the authenticity of their Windows software. If successful in validating Windows, it stores a special license file on the PC for future verification.
After successful validation, the regular update download can continue.
If an instance of Windows does not seem to have a valid license, WGA displays a specific notice to the user and prevents non-Critical updates from being downloaded from Microsoft.

The ActiveX control is downloaded on the first validation and when a new version is available, but the validation itself can be performed any time the user connects to a Microsoft website to update.

On Windows Vista, WGA validation failure has a greater impact. In addition to persistent notification and the disabling of non-critical updates, WGA also disables Windows Aero, Windows Defender, and ReadyBoost. The user is given a grace period in which to then pass validation, after which most of the operating system is disabled and Windows reverts to reduced functionality mode.

Software

Windows Genuine Advantage Validation Tool

When a user installs WGA, 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. If WGA determines that a user's copy of Windows is unauthorized but was installed from seemingly-legitimate media (i.e., the CD and holographic emblem present on real copies of Windows seems genuine), then Microsoft will supply the user with a new CD. 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 WGA a requirement for use of the Windows Update website (and its close cousin Microsoft Update), in part to be sure that customers who use support resources of the company are aware when their software is unlicensed or counterfeit. According to Microsoft themselves, it is legal to run Microsoft Windows without WGA [citation needed]. 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.

Windows Genuine Advantage Notifications

Beginning April 25, 2006, Microsoft began distributing Windows Genuine Advantage Notifications as "critical update" KB905474 to Windows users. Users with pirated copies were exposed to alerts at startup, login, and during use of the Windows OS, stating that they do not have a genuine copy of Windows. Users with legitimate copies are not supposed to see the alerts (although some do anyway). On May 23, 2006, Microsoft updated the program, closing some forms of circumvention, but reportedly not all. It was updated again on May 30, June 6 and June 27, 2006, though some forms of circumvention are still usable. The latest versions do not roll out worldwide at the same time: the dates given are the earliest dates on which the versions appeared, so the actual version being offered in some places will be an earlier version than the latest release. It is still possible to opt out of receiving this update using the "do not show" option at the Windows Update site. In addition to these notifications, Windows Genuine Advantage will also notify users with the message "This version of Windows XP is no longer secure." if users on an XP Operating System are not using Service Pack 2. It will provide a link to help users to upgrade their systems to the new service pack.

The version of Windows Genuine Advantage Notifications released November 29, 2006 had a changed install process to inform the user of what the program does, and can also be set to automatically update to newer versions of Windows Genuine Advantage Notifications. It also informs users that may have a non-genuine version of Windows why their Windows version isn't being reported as genuine. However, unlike previous releases, it is currently only automatically delivered to Windows machines that are using four widely-distributed product keys. It will be distributed to all other machines in the coming weeks.

Windows Genuine Advantage Validation Library

Microsoft includes the Windows Genuine Advantage Validation Library in several products like Windows Defender, Internet Explorer 7, Microsoft Folder and Windows Media Player 11 to validate about the Windows installation.

Microsoft has also launched the Office Genuine Advantage program, which validates installations of Microsoft Office.