Version 2.6.4 is one of the last widely circulated builds of the original Microsoft Toolkit (originally created by a developer known as CODYQX4 ). Subsequent versions have been modified by third parties, making v2.6.4 a “final stable” reference point for many users.
, which is a free, official resource for IT administrators, this "Toolkit" uses a method called KMS (Key Management Service) Emulation