Computers that are running volume licensing editions of Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Server 2008 R2, Windows Vista, and Windows Server 2008 are, by default, KMS clients with no additional configuration needed.
To use the keys listed here (which are GVLKs), you must first have a KMS host running in your deployment. If you haven’t already configured a KMS host, see Deploy KMS Activation for steps to set one up.
If you are converting a computer from a KMS host, MAK, or retail edition of Windows to a KMS client, install the applicable setup key (GVLK) from the following tables. To install a client setup key, open an administrative command prompt on the client, type slmgr /ipk <setup key> and then press Enter.
if you are looking for KMS Client Setup Key