If you’re confused, don’t worry, because I’m still not too sure about exactly how KMS works.
So if I were to have a Windows Server 2008 R2 KMS key, I could have activated that server with the appropriate Windows Server 2008 R2 KMS key, then use it to activate Windows 7 clients. 0xc004d302 Slui.exe 0x2a 0xc004d302 Microsoft Windows Core.