Activating Additional Guest 2012 Servers When 2 OEM Licenses Are in Use

[DrKludge]

We have two Windows Server 2012 Standard (64 bit) servers running as guest OS on an HP Proliant server with VMware EXSi 5.5 as the hypervisor.  The license key for these virtual servers came as OEM with the hardware.

We would like to add more virtual 2012 servers to this box, but I am told that in order to activate more than two, we must acquire additional license keys from Microsoft, not from HP. 

Since the OEM license keys are passed from the BIOS, how would we enter volume or retail licenses once they are purchased?  There does not seem to be a way to change the license key in the 2012 server properties.

HP refers me to VMware licensing, VMware refers me to Microsoft, Microsoft does not seem to know.  I do not want to purchase additional licenses if there is no way to enter them.

[sneddo]

If you buy retail licences and install from retail media you will be prompted for the key during install. Technically, the only difference in the media is a couple of flags in one of the config files to define the product channel, and determines whether the key is pulled from hardware or not.

You can actually change the key later with slmgr.vbs /ipk, or through the windows activation section of your system properties.