Now that Windows 8 and Windows Server 2012 are out, any company that uses KMS keys needs to add the new ones from Microsoft’s Volume Licensing Service Center
https://www.microsoft.com/Licensing/servicecenter/Downloads/DownloadsAndKeys.aspx First, there’s a hotfix for your existing KMS server available here:
Once you request the hotfix, get the email and download it, and install. The install will require a reboot, so if you’ve got this on a critical server you’re going to have to schedule a reboot.
A few change request forms and approval signatures later, you’ll be finally ready to add your shiny new keys in.
Now, here’s the installation instructions from the link above:
If you have a KMS host that is running Windows Server 2008 R2 SP1 or Windows 7 SP1, follow these steps to perform an upgrade: Install this update (KB2691586). Restart the computer when you are prompted.
To install a new KMS host key for Windows 8 activation or for Windows Server 2012 activation, run the following command: cscript %windir%\system32\slmgr.vbs /ipk
Note In this command, replace with the new KMS host key for Windows 8 activation or for Windows Server 2012 activation.Important Every KMS host key is associated with a group of Windows editions. Additionally, a KMS host key that is associated with Windows client operating systems cannot be installed on Windows server operating systems, and vice-versa. This is true for all Windows operating systems except for Windows Server 2003.
If you install a KMS host key on a Windows operating system that is not associated with that host key, you receive the following error message: 0xc004f015: The Software Licensing Service reported that the license is not installed.SL_E_PRODUCT_SKU_NOT_INSTALLEDFor example, you receive this error message if you try to install a KMS host key for Windows 7 on a computer that is running Windows Server 2008 R2.For more information about KMS host keys and about associated groups of Windows editions, see Table 5 in the “Determine Product Key Needs” section of the Volume Activation Planning Guide (http://technet.microsoft.com/en-us/library/dd878528.aspx#E3IAC) .
To activate the new KMS host key on the host computer, run the following command: cscript %windir%\system32\slmgr.vbs /ato
I had to read this more than once. Using the command cscript %windir%\system32\slmgr.vbs /ipk worked fine with the Server 2012 KMS key, but not with the Windows 8 key. You can’t mix both Windows 8 and Server 2012 keys on the same box, but it appears that as long as you enter the Server 2012 key, it also allows Windows 8 clients to register.
The secondcommand cscript %windir%\system32\slmgr.vbs /ato makes the server ‘phone home’ and completely register the keys.
Once you’ve got a client registered, you can use the command cscript %windir%\system32\slmgr.vbs /dli to show you when you registered, to which server etc.
Note: The Volume Activation Management Tool is useless for this, as it won’t recognise your new keys.