Windows 8.1 and Server 2012 R2: Quick start guide for sysadmins

What do you mean you forgot your key?

IT Crowd. Source: Channel 4 / 2entertain

Sysadmin blog Windows 8.1 and Windows Server 2012 R2 are now officially available. New shiny toys for the kids, but how does a sysadmin license these new products?

This post assumes you're already up and running with Windows 8 and Server 2012, but I'll quickly go over the basic requirements:

You'll need to obtain your Server Key Management Service (KMS) key from Microsoft’s Volume Licensing Service Center.

Clients by default will have a Client KMS key, but if you want to check, here's the list from Microsoft.

To clarify how a KMS works - a client has a Client KMS key which is generic globally, and tells the client to check in with a KMS Server to be licensed. The KMS Server talks back to Microsoft, using its Server KMS key which is special to your Microsoft agreement to keep itself activated.

The KMS Server will manage the licensing side of things, but there's a minimum amount of clients that need to have requested activation before the server starts approving anything. Twenty-five Client Operating Systems (eg, Windows 8.1) and five separate Server Operating Systems are the minimums. KMS clients attempt to check in every seven days, but have up to 180 days before licensing becomes invalid.

Confused yet?

KMS also needs a DNS entry (which can be customised) so clients know how to get to the KMS Server; the settings required are listed here.


If you're not using a brand new Windows Server 2012 R2 server as your KMS Server, you'll need to download the relevant update.

If you don't do this and try to activate, you'll see the following message:

slmgr.vbs /ipk xxxxx-xxxxx-xxxxx-xxxxx-xxxxx

So trust me, you need to install the patch and reboot.

Make sure you're using the KMS Server key relevant to the OS you're putting the key on, not what clients you're planning to license (ie, KMS Server 2012 R2 key goes on any Server OS - 2008 to 2012, and will allow you to license both Windows Server 2012 R2 clients and Windows 8.1 clients).

Once you've successfully added the key with the slmgr.vbs /ipk xxxxx-xxxxx-xxxxx-xxxxx-xxxxx command, you can force it to activate with the command slmgr.vbs /ato. Normally it takes a few seconds for the dialog box to show the results.

You can then see the stats on how many KMS clients are activated, as well as checking that you're ready for 8.1 and R2 with the command slmgr.vbs /dlv. Near the top of that dialog box will be a description which should end with VOLUME_KMS_2012-R2 channel.

You're now good to go with the exciting world of KMS licensing on the latest operating systems from Microsoft. ®

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