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.
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 (Windows XP), and the "Hide" option in the right-click menu of Windows Update in Control Panel (Windows Vista/7/8).
Despite its name it does not actually evaluate the integrity or security of any computer.
As of July 2006, the latest update blocks management by other means.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.The WGA Validation Library is also included in the Microsoft Security Essentials 2.0 and validate the Windows installation whether it is legitimate or not.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.