KMSpico is an unauthorized, third-party software utility designed to emulate a Microsoft Key Management Service (KMS) server locally on a user's machine.

However, as KMspico's popularity grew, so did the scrutiny. Microsoft, not pleased with the existence of such tools, began to take measures to counteract their effects. The cat-and-mouse game between KMSSoft and Microsoft had begun, with each side trying to outmaneuver the other.