Windows Genuine Advantage (WGA) is an anti-piracy system created by Microsoft that enforces Microsoft Windows online validation of the authenticity of several recent Microsoft operating systems when accessing several Microsoft Windows services, such as Windows Update, and downloading Windows components from the Microsoft Download Center. Specifically, WGA covers Windows XP and Windows Vista. It does not cover Windows 2000, Windows Server 2003 or the Windows 9x family. However, certain downloads and non-critical updates from the Download Center for Windows 2000 require validation.
It also advertises Service Pack 2 for Windows XP, which requires manual intervention to disable. Previously voluntary, it became mandatory for use of these services in July 2005.
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:
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.
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 Windows Genuine Advantage 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 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.
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.
In September 2005, Microsoft filed lawsuits against a number of companies that sold unauthorized copies of software to consumers. The cases are important because the leads came from customers who learned they had counterfeit software via the Windows Genuine Advantage program.
On November 16, 2005, Microsoft released a standard Netscape WGA plug-in to complete the Windows validation process from Mozilla Firefox and other Gecko-based browsers (including Netscape) - although it does not use the Firefox extensions system, and thus is not supported by the latest version of the browser. This has garnered more criticism, since it still does not work in other NPAPI supported browsers such as Opera. Another workaround was released on December 25, 2005 to bypass WGA authentication by using a valid hash generated by a remote system. Microsoft responded with a cease and desist letter to the website host, and the workaround was taken down on January 6, 2006. Many people continue to validate on the Microsoft website from a public computer using a genuine copy of Windows, then write down the hash and continue to use it at home or work. As of July 2006, Microsoft has not devised a way to prevent this method of circumvention. On May 4, 2006 Microsoft announced lawsuits for allegedly distributing unauthorized copies of Windows against eDirectSoftware of Montana, and Chicago-area resellers Nathan Ballog and Easy Computers.
Various workarounds to get past WGA authentication have been released on the Internet. Before Microsoft issued official instructions on removing the WGA Notifier (a desktop application which resides in the system tray and periodically displays messages, reminding users to authenticate their operating system), users simply had to remove 2 files in order to get rid of the software from their system.
In September 2006, Microsoft dropped various required validations on programs such as ActiveSync.
A tool has been released by a firewall vendor to prevent WGA Notifications transmitting information from one's PC.
Despite this, Microsoft is currently being sued under anti-spyware statutes over WGA's non-disclosed "phone home" behaviour. The outcome of the lawsuit has not been determined.
According to an editorial on the arstechnica.com technology website, WGA reported around 22% of 500 million Windows computers as failing the test; of these less than 0.5% were due to pirate software, with the balance (over 20%, or 90% of all positives) related to non piracy issues. Microsoft "refused to comment on the rate of pure false positives" beyond saying it was "under 1%" (or as stated, at most around 5 million users affected).
On August 25, 2007, the Microsoft WGA servers suffered an outage, resulting in many legitimate copies of Windows XP and Vista being marked as counterfeit. The issue was solved about twelve hours later. According to Microsoft, "fewer than 12,000 systems were affected worldwide.