In July of 2005, Microsoft unleashed Windows Genuine Advantage (WGA), which required users of Microsoft's Windows Update, Microsoft Update, and Microsoft Download pages to install the first component of WGA, subsequently dubbed WGA Validation. One of the first pieces of software requiring a WGA check was Windows Defender. At that time, Microsoft began requiring that you either installed WGA Validation, or you didn't use any of Microsoft's download sites. (It was still possible to get Microsoft's security patches through Windows XP's Automatic Updates without installing WGA Validation.)

WGA Validation is a piece of code that runs in Windows that determines all on its own whether the installed copy of Windows it's running in might have been pirated or improperly authorized. Earlier this year, Microsoft delivered the second component of WGA, called WGA Notifications. Its purpose is to inform the user that WGA Validation has found a problem with the installed copy of Windows. It also tries to help the user find a solution, including asking for money to re-license Windows.

WGA Notifications ran into a buzz saw of criticism when an early version of it re-connected with Microsoft servers in the background on a daily basis. Even more importantly, there was a wave of reported false positives. WGA Notifications is technically an optional install from Windows Update or Automatic Updates, but the manner in which you choose not to receive it is not intuitive for most users.

WPA and WGA work together on Windows XP machines they're installed on. WGA is also capable of running solo on Windows 2000 computers.

Enter Windows Vista. Microsoft took the opportunity of a new Windows release to unify the processes of WPA, WGA Validation, and WGA Notifications. Possibly because of the bad press WGA received over the summer, the Vista's new anti-piracy system is called Software Protection Platform.