Downgrading Windows Server 2012 OEM

A little known fact about Windows Server 2012 (WS2012) Standard and Datacentre editions is the fact that you can run these operating systems as a Hyper-V host and use a variety of operating systems as virtual servers. The limitation on the number of virtual machines is governed by licensing. You can install two virtual machines per 1-2 physical processors on a host server if you have WS2012 Standard. If you want 3-4 virtual hosts running on this server, you can purchase another WS2012 Standard license, or you could purchase WS2012 Datacentre, which allows you to install as many virtual servers as your physical machine can handle.

Granted, this is not new for those who have purchased a Volume License agreement. However, not many realise that this is also available in the System Builder or OEM channel.

There is a lot of information on the OEM Partner Center here –

Therefore, if you are running WS2012 as a HyperV Host, you can install up to two virtual servers, which can be any of the following – WS2012 (standard or datacentre), WS2012 Essentials, WS2011 Essentials, WS2008R2, WS2008, WS2003.

The big question is “How to I activate the servers?”

To downgrade the virtual servers, you will need to implement the following steps:

  1. Obtain genuine Windows Media and a corresponding product key.
    1. It should come from a previously legally licensed version from the OEM or Retail channel. (Yes, that is correct! You can grab a DVD and a product key from a previously activated and installed server. It does not have to be yours)
    2. If you have a volume license agreement, then you must use the volume license media and product keys.
  2. Install the virtual server using the media and corresponding product key above.
  3. When the server needs to be activated, you can attempt to do this online. If it works, great! If you are not able to activate the product key because it had been previously activated, you will need to call the Microsoft Activations service.
    1. Call the number as listed for your country.
    2. Select Windows or Windows Server activation.
    3. Type in the installation ID as shown on your screen and wait to be transferred to a service representation.
    4. Explain to the representative that you are downgrading your WS2012 installation and need to activate the WSnnnn installation.
    5. When asked, provide the installation ID, and the representative will provide you with the confirmation ID to activate the server.

Note that the other OEM licensing rules still apply. You cannot transfer this license to another physical machine, nor can you put the virtual machines on another physical host. The host and the virtual machines must live and die on the physical machine that they are licensed for.

19 thoughts on “Downgrading Windows Server 2012 OEM”

  1. I have purchased a HP Windows 2012 Datacenter ROK which came with a new HP server. I have installed this on the server and set up HyperV with the intention of installing four Windows 2008R2 virtual servers (HyperV) . To activae the 2008R2 servers, I am hoping to use a product key off an existing OPEN license which was purchased for a single W2008R2 server a couple of years ago. Will this work ? Or must I use a key off an existing OEM or retail version of 2008R2 ( dont have one)

      1. To clarify to save others from the pain of trying to get information on activation from Microsoft or the web.

        To downgrade from HP 2012 R2 ROK key to Server 2008 R2 we did as below, easy.

        Go to to request the downgrade media and key.

        While waiting for this to arrive in post we installed Server 2008 R2 server using installer from MS volume licence website (i.e. a VL install) as ESXi 5.5 U1 free virtual machine. Updated vmx to set host bios = true. We then completed our pre-production setup including domain join, apps etc.

        Once HP downgrade key arrived from HP simply right click computer > properties > change product key > enter the HP Server 2008 R2 Virt key from HP. This activated NO PROBLEMS (in our case).

        We had spent hours on the phone with HP/Microsoft based on what we read online but were unable to get definitive answer. For us we could activate VL install using HP OEM ken no problem. Hope this helps.

    1. In the strictest sense, you cannot officially downgrade a OEM/ROK using Open media and keys according to the OEM Partner Center documentation. You CAN use them if you are licensed to use those keys, but they will count towards your Open license usage.
      Technically, it will work.
      If you want to be compliant, you should order the Media Downgrade kit from HP.

  2. This is the most broken process I have ever seen Microsoft publicly release as a solution. I was literally told by Microsoft Professional Services today that if I wanted to downgrade one of my licensed 1+2 VM’s to Essentials 2012 I was to go and use somebody else’s media and key. If it failed to activate I was to follow your instructions to call in and activate and it it activated I was to call in and get the activation code changed.

    In the end if you want to install Essentials as a VM which you are licensed to do you must download Essentials from any legal source along with an install key. Install Essentials then use DISM ( to transition your VM’d Essentials to Server 2012 with Essentials Goodies at which point you end up with a broken server as it won’t update properly and reporting is screwed up.

    I am floored Microsoft has put in place a process that is so poorly documented and leaves the end user with a broken install.

  3. How did everyone miss this part here in the MS OEM site??
    It says right there that you can use any media and any license key you want.

    Downgrade media and product keys

    End users may use any existing software media or product key to install and activate downgrade or down-edition software*. The downgrade software and product key may be from any channel (Volume Licensing (VL), OEM, or retail) and does not need to match the channel license type that is assigned to the server.

    Acquiring media and product keys
    •End user provided. Customers who have existing solutions or environments with a previous version of Windows Server may use any existing media and product key to exercise their downgrade rights. The downgrade software and product key can be from any channel (OEM, VL, or Retail).
    •Microsoft provided. Prior to September 30, 2012, Microsoft provided downgrade media and product keys directly to end users via a Windows Server fulfillment website. Due to low utilization rates, Microsoft no longer provides this service.
    •OEM partner provided. Direct OEM partners with a royalty OEM agreement (HP, Dell, etc.) have the option to distribute downgrade media and product keys directly to end users, per end user request. This is optional, so not all direct OEMs will provide this service.
    * A down-edition is a lower edition of Windows Server software. For example, lower editions of Windows Server Datacenter edition would include Windows Server Enterprise, Windows Server Standard, and Windows Server Web edition.

    1. Hi,

      I am not getting your quoted text via the link. The OEM Partner Center link quite clearly states that if you have OEM or Retail, you use OEM or Retail licenses and media. If you have VL, you have to use the VL licenses and keys.

      From the link you supplied:
      The downgrade process
      Follow these steps to downgrade to a previous version of Windows or Windows Server software:
      1. Obtain genuine Windows media and a corresponding product key for the version of Windows that is eligible for downgrade.
      The media should come from a prior legally licensed version from the OEM or Retail channels.
      End users who are licensed separately through Microsoft Volume Licensing (VL) may provide their VL media and key to a system builder to facilitate the downgrade on their own systems.

  4. Hi Boontee,

    Just found your blog after another colleague refered the site as a usefull blog and the solution to the 2012 server reboots. Just noticed this post and wanted to clarify that WS2012 Datacentre is also up to 2 processers; if you host many VM’s and may run on more processors you do need multiple copies of DataCenter also.

    1. Datacentre edition is licensed the same as Standard. Thus, you need a license for every 2 physical cores per server. A dual processor server will need 1 license. A 4 processor server will need 2 licenses, and so on.

  5. We got Windows 2012 OEM and need to downgrade to Windows 2008 R2? Problem is we cannot find the damn OEM 2008 R2 installer, may we just use the volume VL installers and still activate it as OEM?

        1. From the post, “Acquiring media and product keys
          •End user provided. Customers who have existing solutions or environments with a previous version of Windows Server may use any existing media and product key to exercise their downgrade rights. The downgrade software and product key can be from any channel (OEM, VL, or Retail).”

          You must have your own copy of the Windows Server 2008 R2 media and product key. If you do not have this, you should contact your manufacturer.

  6. Actually is our supplier that will provide us of a Windows 2008 R2 VL (Open) media and key. They tell us is ok to intall from ANY media with ANY key provided we do really own a Windows 2012 OEM licence (as we do) which will be given to Activation Center as proof in order they generate a new OEM key. That!

      1. Already done. Found this, there is no legal limit on what type of media to use, of course there may be a “technical” limitation once we attemp to do it the way I describe.

        “14. DOWNGRADE. Instead of creating, storing, and using the software, for each permitted instance you may create, store, and use an earlier version of the following editions of the software:
        · Windows Server Standard
        · Windows Server Enterprise
        · Windows Web Server
        · Windows HPC Server Operating System
        This agreement applies to your use of the earlier versions of the editions listed above. For the avoidance of doubt, by electing this downgrade option: (i) you will not have the right to create, store or use a greater number of instances of the software than are permitted under this agreement, and (ii) you will need to acquire licenses for the number of processors in the physical server in accordance with Section 2 of this agreement. If the earlier version includes different components not covered in this agreement, the terms that are associated with those components in the earlier version of these editions apply to your use of them. Neither the manufacturer or installer, nor Microsoft is obligated to supply earlier versions or other editions to you. At any time, you may replace an earlier version or edition with this version and edition of the software.”

        Download license here: Server_2012 Standard_English_e9290a42-353a-4709-84cb-321c172f29b9.pdf

        Find End User License Terms for Microsoft Software Licensed by Microsoft or the Computer Manufacturer:

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