Versions labeled with arbitrary numbers like "491 Final" or "Repack" are often modified by unknown parties and carry severe risks:
An automated script that attempts to activate the software with minimal user input.
: It emulates a Key Management Service (KMS) host. Genuine KMS activation is a method used by large organizations to activate hundreds of computers at once. The toolkit mimics this process to fool the software into thinking it has been legitimately activated by an organization's server.
Version was the final iteration before Microsoft patched many of these methods with the introduction of Windows 11 and Office 2021.
If a user downloads a "legit" copy of Microsoft Toolkit 491 Final, here is what the activation process would look like:
