KMSpico is a popular tool used to activate Windows operating systems and Microsoft Office products. It works by emulating a Key Management Service (KMS) server, which is typically used in large organizations for volume activation. KMSpico tricks Windows into believing that it is being activated by a legitimate KMS server, thus bypassing the need for a genuine license. This method, however, is not officially supported by Microsoft and may be considered illegal. Additionally, using KMSpico can pose security risks as it often comes from unverified sources and might contain malware.