When configuring a Horizon View environment for Windows 8 activation, I was receiving Event ID 1017 Installation of the Proof of Purchase failed. 0xC004F050
The KMS Server is a Windows 2008 R2 VM which has HotFix KB2757817 installed to allow activation of Windows Server 2012 or Windows 8 on a Server 2008 R2 VM.
When trying to add the Windows 8 KMS key using
slmgr.vbs /ipk <Windows8KMSKey>
Resulted in the error ‘On a computer running Microsoft Windows non-core edition, run ‘slui.exe 0x2a 0xC004F015 to display the error text.
Error: 0xC004F015
This then meant that my Windows 8 VM’s where stuck in the ‘customizing’ state in Horizon View Administrator.
Resolution
The fix is simple you need to use a Windows Server 2012 KMS license rather than a Windows 8 KMS license.
slmgr.vbs /ipk <Windows2012KMSKey>
Which returns ‘Installed product key XXXXX-XXXXX-XXXXX-XXXXX successfully’
Then last of all run the command
slmrg.vbs /ato
Which will activate the KMS license.
VMFocus 
Hi! I have successfully installed the product key. I was prompted –> (‘Installed product key XXXXX-XXXXX-XXXXX-XXXXX successfully’). But when I try to do (slmrg.vbs /ato), I still get the error 0xC004F074 “The Software Licensing Service reported..etc…” Help please. 😦
Hi Kim, depending on your operating system you might need to download a specific update to enable Windows 8 activation
see KB http://support.microsoft.com/kb/2757817