I misread something or I'm doing a terrible mistake here, hopefully you guys can help me.

I have set up a Hyper-V Server 2016 on my physical machine (or bare metal as it's called) which has 1 processor with 4 cores.

Afterwards, I connected with Hyper-V Manager and I set up 2 VMs and installed Windows Server 2016 Datacenter in both of them. So far so good.

However, when I set up a 3rd VM and installed Windows Server 2016 Datacenter in it, Windows said that my key is already used in another machine.

But... I thought I can create unlimited VMs with the Datacenter edition... right?

What am I doing wrong?

EDIT1: I exported my VMs (the ones with the datacenter key) AND I removed hyper-v server from my host machine and erased it. Then I installed Windows Server 2016 Datacentre with the Hyper-V role and used the Datacenter key to activate it. Windows still reports that my key has already been used on a different device. Error code: 0xC004C008

EDIT2: I re-imported the VMs to my host machine and I removed the datacentre key from the VMs and put the AMVA key TMJ3Y-NTRTM-FJYXT-T22BY-CWG3J (I found it here) to all of them. The host machine though remains dis-activated

EDIT3: I called Microsoft and activated the host machine by phone. At first the automatic activation system told me that I cannot activate this key and that I had to get another one. But actually I had to intentionally make a mistake during the automatic phone activation in order to reach another human being on the line. Finally, after I spoke with a human, my host machine and VMs were activated without problems. Thank you all!

  • Datacenter VMs on (free) Hyper-V-Servers isn't the best option. You confuse activation keys, licensing on OS level and so on, I think
    – Lenniey
    Nov 7, 2018 at 15:15
  • look for answer of putch in this thread: social.technet.microsoft.com/Forums/en-US/… Nov 7, 2018 at 15:16
  • Call Microsoft and get a different key.
    – Greg Askew
    Nov 8, 2018 at 11:03
  • Yes! that did the trick. I'll update my question with the results. thank you all! Nov 8, 2018 at 12:45

1 Answer 1


What you did wrong is adding the key. Which you needed because... ah.

  • You should have installed Datacenter on Hyper-V. With a proper key that would auto activate any VM on it. Hyper-V on the host is not beneficial licensing wise in most cases, and technically means no auto activation.
  • There is pretty much zero benefit from installing Datacenter on a VM. Benefits are mostly licensing, on a level that is not useful outside of the host (due to the host on Datacenter auto activating client VMs).

That sort of sums it up.

  • So, for the OP, what you're meant to do is to install Datacenter 2016 on the host, with the Hyper-V role, and then install your VMs. Nov 7, 2018 at 19:55
  • @MichaelHampton Thanks both! I'll try this now and get back here afterwards! Nov 8, 2018 at 7:17
  • I installed Windows Server 2016 Datacentre on my host machine and Windows still reports that my key has already been used on a different device. Error code: 0xC004C008 Nov 8, 2018 at 10:05
  • 1
    Because oyu mised the first line - you added a key. On the VM's use the standard default AVMA key. It should be precoded (it IMHO is on volume ISO's): Windows Server 2016 Standard C3RCX-M6NRP-6CXC9-TW2F2-4RHYD - this one will NOT activate (so yes, it actually is from public documentation) but will look for AVMA. altaro.com/hyper-v/…
    – TomTom
    Nov 8, 2018 at 10:11
  • 1
    The host machine is deactivated because you used up all your activations and MUST call Microsoft to bypass the internal limitation of the keys. Simple like that. You can not undo a mistake done without calling MS support.
    – TomTom
    Nov 8, 2018 at 12:17

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.