To enable KMS functionality, a KMS key is installed on a KMS host; then, the host is activated over the Internet or by phone using Microsoft’s activation services. Computers running Windows 7 or Windows Server 2008 R2 can both serve as KMS hosts.
Windows Vista, Windows Server 2003, and Windows Server 2008 can also serve as KMS hosts. The KMS clients that a KMS host can activate are dependent on the host key used to activate the KMS host. For more information about KMS host keys, see the Volume Activation Planning Guide.
Install and activate a KMS key on a Windows 7 or Windows Server 2008 R2 computer by using an elevated command prompt:
To install a KMS key, type slmgr.vbs /ipk <KmsKey> at a command prompt.
To activate online, type slmgr.vbs /ato at a command prompt.
To activate by using the telephone, type slui.exe 4 at a command prompt.
After activating the KMS key, restart the Software Protection Service.
Windows 7 and Windows Server 2008 R2 display the warning shown in Figure 1 any time administrators install a KMS host key by using the UI (Users will not see this warning if they install a KMS host key by using the Slmgr.vbs script). This message prevents accidentally installing a KMS key on computers that administrators do not intend to be KMS hosts.
Figure 1 The KMS key warning
To verify that the KMS host is configured correctly, check the KMS count to see whether it is increasing. In the Command Prompt window on the KMS host, type slmgr.vbs /dlito display the current KMS count. Administrators can also check the Key Management Service log in the Applications and Services Logs folder for event ID 12290. The Key Management Service log records activation requests from KMS clients. Each event displays the name of the computer and the time stamp of each activation request.