KMS activation of Windows 8.1 and Windows Server 2012 R2

In order to activate Windows 8.1 and Windows Server 2012 R2 using KMS hosted on previous generation of Windows operating system, Microsoft has published following kb article http://support.microsoft.com/kb/2885698/en-us .
After installing the update, you will be able to install and activate your KMS key for Windows 8.1 and (or) Windows Server 2012 R2.
Procedure for installing the KMS host key is the same as installing KMS host key from previous versions of Windows operating systems:

cscript %windir%\system32\slmgr.vbs /ipk <KMS host key>

You will experience following error if you are installing KMS host key on Windows operating system that is not associated with that host key:

0xc004f015: The Software Licensing Service reported that the license is not installed. SL_E_PRODUCT_SKU_NOT_INSTALLED

 For example:

• Windows 7 KMS host key install on Windows Server 2008 R2
• Windows 8 KMS host key install on Windows Server 2008 R2, Windows Server 2012
• Windows 8.1 KMS host key install on Windows Server 2008 R2, Win Server 2012 and R2

 Activate the KMS host key using:

cscript %windir%\system32\slmgr.vbs /ato

In my case the KMS server was using proxy for connecting to internet and the user activating the KMS host key was not having proper permission to access the Microsoft's Internet Activation Servers. The activation was failing with following error message 0x8004FE92:

On a computer running Microsoft Windows non-core edition, run 'slui.exe 0x2a 0x8004FE92' to display the error text. Error: 0x8004FE92

Running the 'slui.exe 0x2a 0x8004FE92' does not provide a lot of help:

 

After providing proper Internet access for the user, activating the KMS host key has completed successfully. More about 0x8004FE92 error message can be found on http://support.microsoft.com/kb/2009934/en-us .