KMS activations are not permanent; they are valid for .
For the system to start working, a minimum number of clients must connect. For Windows 10, the threshold is 25 unique physical or virtual computers .
| Feature | KMS (Key Management Service) | MAK (Multiple Activation Key) | | :--- | :--- | :--- | | | Requires local network access to Host. | Requires direct internet access to Microsoft once. | | Threshold | Requires 25+ clients to start working. | No threshold. | | Reactivation | Every 180 days (automatic). | Perpetual (rarely needs reactivation unless hardware changes). | | Best For | Large enterprises, dynamic environments, air-gapped networks. | Small branches, machines rarely connected to the corporate network. |
It is important to distinguish KMS from the other volume activation method, MAK.
Key Management Service (KMS) is a volume activation method used by organizations to activate Windows 10 computers within their internal network. This process requires a (a server configured to manage licenses) and KMS clients (the computers to be activated). KMS Activation Guide