Windows Genuine Advantage (WGA) was an anti-infringement system created by Microsoft used to validate the licences of several Microsoft Windows operating systems upon accessing services such as Windows Update and Microsoft Download Center.

Copyright infringement is the use of works protected by copyright without permission for a usage where such permission is required, thereby infringing certain exclusive rights granted to the copyright holder, such as the right to reproduce, distribute, display or perform the protected work, or to make derivative works. The copyright holder is typically the work's creator, or a publisher or other business to whom copyright has been assigned. Copyright holders routinely invoke legal and technological measures to prevent and penalize copyright infringement.