KMS on 2008 R2 : the software licencing service reported that the computer cannot be activated. No key Management service could be found

hi,

We are trying to activate 2012 R2 KMS client against a 2008 R2 KMS server but we got error of "the software licencing service reported that the computer cannot be activated. No key Management service could be found"

2008 R2 and Windows 7 KMS client can activate against the but not 2012 R2 KMS client

we already installed the support for  Windows Server 2012 R2 clients to Windows Server 2008 R2 http://support.microsoft.com/kb/2885698/en-us but still cannot activate 2012 r2 KMS client

Any known issue?

thanks