Windows 2008 KMS host

[netmgr001]

Just got a quick question about enabling a Windows 2008 enterprise box as a kms host.

 

The server had already previously been activated with a w2k8 MAK. I've tried running the slmgr -ipk

command to add a Windows Server 2008 R2 KMS key so i can activate Windows 7 KMS clients and then the

-ato command, but when i run the -dlv command afterward it doesn't come back as saying it's a KMS host.

 

Do i need to uninstall the existing MAK key for it to operate as a KMS host for internal win7 clients,

would that be a -upk command, and do i need to dig out the original MAK key for use with the command ?