Install the KMS Server:

To get KMS to start activating Windows 7 you need 25 unique Windows 7 installs to check in with the KMS server.

To activate Office 2010/2013 you need five unique installs.

The easiest way to accomplish this is to set up a test pool with your parent image and have it create 25 non-persistent desktops.

http://technet.microsoft.com/en-us/library/cc303280.aspx#_Install_KMS_Hosts

To enable KMS functionality, a KMS key is installed on a KMS host, then the host is activated using Microsoft hosted services. Computers running Windows 7 and Windows Server 2008 can both serve as KMS hosts.