KMS Activator is a software tool used to activate Microsoft products, including Windows and Office, by simulating a Key Management Service (KMS) server. Allows activation of Microsoft software via KMS server simulation. Works offline: Can activate systems without requiring an internet connection. Activation expires after 180 days, requiring renewal. Risk of violating Microsoft’s terms of service with KMS activation. May cause system instability if used for extended periods. Can be used on various editions of Office and Windows.