use the AVMA keys

slmgr /ipk:<AVMAKEY>

AVMA keys for Windows Server 2016

Datacenter   TMJ3Y-NTRTM-FJYXT-T22BY-CWG3J

Standard   C3RCX-M6NRP-6CXC9-TW2F2-4RHYD

Essentials   B4YNW-62DX9-W8V6M-82649-MHBKQ

There's no such thing as windows server 2016 core.  there is with or without desktop experience.

WHY are you trying to change the edition?

(Why trying to change the edition)
I was running Eval versions, and this is what I read a while back to use.
(I do not remember where I read it, that was a few years ago.)

Using the following command.

Dism /Online /Get-CurrentEdition

Select allOpen in new window

Gives the name of:
So it needs to be changed to:
During the Activation process.

Running the command (I've tried several times this evening before posting this topic.)

slmgr /ipk KEYHERE

I get

---------------------------
Windows Script Host
---------------------------
Error: 0xC004F069 On a computer running Microsoft Windows non-core edition, run 'slui.exe 0x2a 0xC004F069' to display the error text.
---------------------------
OK  
---------------------------

I pasted slui.exe 0x2a 0xC004F069
And I do not get the error.

(There's no such thing as Windows server 2016 core.)
I got the CORE name from Microsoft while researching setting up a Server Farm and wanted the best way to utilize Windows Server 2016, and I found out that using CORE was much better suited for lower overhead.
There was either the Desktop Experience or Core Edition (Non-Desktop Experience).
This is one of the articles from Microsoft where they specify
What is the Server Core installation option in Windows Server?.

So, I call it Windows Server Core 2016 (or) Windows Server 2016 Core.

there is no server 2016 core only standard, enterprise and essentials editions

so the target edition would be ServerDatacenter.. if you installed with Desktop Experience you can't change it to without desktop experience. That was one of the changes in 2016 

you also can't add desktop experience. 

David.
I never said I had installed Desktop Experience and wanted to change it to Core (Non-Desktop).
I have 2 Desktop Experience VMs on this Server.
And the rest are Non-Desktop.

You may not call it Server Core 2016, but that is what it is referred to by not only Microsoft but everywhere else.
A quick Google Search for What is Windows 2016 Server Core provides many results from Microsoft as well as other online magazines and videos.

I am not here to challenge anyone over the Name of Server Core.
I just need to know what I can do about the Activation of these Systems.

Here is the screenshot of one of the Servers which is already Activated.

And this is a screenshot of the Evaluation Version of the Server Core.

Is this the version that was available via Software Assurance that was updated frequently and had something like an 18 month shelf life?

When you install Windows Server using the setup wizard, you can choose between Server Core or Server with Desktop Experience install options. 

it still is not an edition the editions are standard/datacenter/essentials. just change it to serverdatacenter

converting the trial version of Server Core is supported starting from the release of Windows Server 2016 14393.0.161119-1705.RS1_REFRESH). 

Which is unfortunately a later version  than on the evaluation page. 

try this non eval download https://www.technig.com/free-download-windows-server-2016-iso-file/

Thanks for the link, I will download it for future installs.

As for using
serverdatacenter
That is not what the core is.
It has to be.
serverdatacentercor
As I showed above.

If you try to activate without the cor at the end you get an error saying it is the wrong version.

I will post later on the exact error that is received when trying without cor.

I will check to make sure that cores I have are up to date on patches and updates and try it again.

Phillip.
No it isn't.

Sent a request from Google drive.

With the help of David, I have successfully installed and licensed one core copy.
I could only successfully license 2 Eval Desktops and 5 Cores, so now I have to install the Retail copy 9 more times.

This will be a long ordeal, but the good thing is I have time to do it; I don't have to do it all in one shot.

Thanks for the download, David; that was very cool of you to do this for me.
Wayne

David, maybe you can help to explain this.
On my backup server, which I will be doing a license for within the coming weeks.
There are 6 VMs, and 4 can be upgraded, and 2 cannot be.

Checking the Build info using: Get-ComputerInfo.
The top is upgradeable, and the bottom is not.

WindowsBuildLabEx : 14393.693.amd64fre.rs1_release.161220-1747 (Upgradeable)
WindowsBuildLabEx : 14393.2248.amd64fre.rs1_release.180427-1804 (Not-Upgradeable)

no idea kill the non-upgradable and just use the upgradeable. or the full source files provided

on the vm's use the AVMA keys I provided.

Thanks a bunch, David.
I placed the License Key inside the /Sources/PID.txt and recreated the ISO file.
And now, installing all these VMs is a lot simpler.
Your ISO was a lifesaver, to say the least.