(KMS is used to activate Microsoft products on the local network without connecting to Microsoft services. Physical machines and virtual machines can be activated (but the number of machines must reach or exceed the activation threshold, 5 in server series and 25 in windows series). Kms client installs kms client key (gvlk). Find kms server through DNS or static configuration, and then contact it through remote procedure call (RPC) and try to activate it, Although kms greatly reduces the activation work of computer administrators, the official kms service still has many restrictions. Therefore, there are an unlimited number of KMS service agents in the market, such as py kms, vlmcsd and so on.)