KMSAuto is a tool designed to activate Microsoft products, such as Windows and Office, without a genuine license. It works by emulating a Key Management Service (KMS) server, which is typically used in volume licensing to activate software within organizations. KMSAuto interacts with the software to bypass activation checks and provide full functionality. While it can be effective, using such tools is illegal and poses risks like malware infections or system instability. For legal and secure activation, it is recommended to purchase a genuine license from Microsoft or an authorized distributor.