As of 2024 and 2025, Microsoft Defender identifies virtually all known versions of Microsoft Toolkit as or "PUA:Win32/Keygen." While some argue this is a "false positive" because the tool does hack the licensing system, it is a true positive: Microsoft does not want this software on your computer.
Released several years ago, version 2.5.1 was specifically designed to handle activation for Windows 8.1, Windows Server 2012 R2, and Microsoft Office 2013. It operates using KMS (Key Management Service) Microsoft Toolkit 2.5.1 Download