As you've probably heard already, when Windows 8.1 releases on October 18, 2013 there's already a stability and improvement patch waiting in the wings. In Windows 8.1: What to Expect While You're Expecting, you can read about that if you missed it. But, as time progress before and after release don't be surprised to see other updates released to bring Windows 8.1 compatibility to other systems. With Microsoft releasing so many product updates at the same time as Windows 8.1, there's sure to be something they missed.
There's an update now available that brings Windows 8.1 support to your Key Management Service (KMS) host. KMS is a service that runs on a computer in the organization to supply enterprise licensing activations. The update is intended for Windows Vista Service Pack 2, Windows Server 2008 Service Pack 2, Windows 7 Service Pack 1, Windows Server 2008 R2 Service Pack 1, Windows 8, and– all of which can be used as a KMS host.
The update is available for download from here: Article ID: 2885698