On Windows Vista without service packs, WGA validation failure has a greater impact.

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.

This behavior however has been removed in Service Pack 1 of Windows Vista in favor of prominent notices on systems believed unlicensed.

Microsoft also offers discounts to people who want to purchase a legitimate copy of Windows but do not have a valid CD.

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.

However, unlike previous releases, it started being only automatically delivered to Windows machines using four widely distributed product keys.

As of version 7, Internet Explorer no longer requires the user to pass a Windows Genuine Advantage test in order to download or install the software.

[10] 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.

[citation needed] A tool has been released by a firewall vendor to prevent WGA Notifications transmitting information from one's PC.

[12] Through Windows Genuine Advantage, Microsoft collects the following data:[13][14] On October 20, 2008, many users of Windows XP in China received a black desktop, as Microsoft introduced its WGA system for Chinese language systems[15][16][17] in an effort to combat copyright violation, which is extremely common in China.

Since the majority of users in China run unlicensed copies of Windows, many users have experienced what is described as a "black screen syndrome", where the operating system changes the desktop background to a black screen, as well as displays constant warning messages.

[21] Even if WGA does not really make the operating system unusable, no updates except critical ones can be downloaded from Microsoft.

[38] According to an Ars Technica editorial, WGA reported around 22% of 500 million Windows computers as failing the test; of these less than 0.5% were due to unauthorized software, with the balance (over 20%, or 90% of all positives) related to edge cases.

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).

[40] 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.