Can I restore my OEM system to alternate hardware or to a virtual machine with Unitrends?


Customers ask often about limitations of OEM installations and the implications on recovery.


You have a Windows system deployed with an OEM license key and want to know what recovery options you might have with Unitrends.



Microsoft issued OEM keys can exclusively be recovered back to the original motherboard contained in the original purchased hardware. They are system bound on original deployment.  A substantial cost difference is provided to the customer to accept this limitation vs purchase of a full retail or Volume License key.  

Even a warranty replacement of the motherboard in the same chassis will void Microsoft's activation key for any OEM deployment.  This is not a restriction on data recovery but on the hardware vs license association itself enforced by Microsoft clarified in their OEM terms.  

This is discussed in the following from Microsoft:  Transfer of OEM Licneses. Licenses cannot be transferred to new hardware or moved to virtual at all.  Baremetal recovery of an OEM server after mainboard or chassis replacement is not supported under Microsoft license terms.    

Server OEM licenses that have Microsoft SA purchased within 90 days or original system purchase are granted a Volume License equivalent transfer right, however, transfer of any OEM license that does include such rights requires redeployment and reactivation of that license. Additionally, Licenses purchased and deployed within the boundaries of the German nation also include such rights.  

Restore of a system or moving/copying OS drives from one chassis to another will result in activation Microsoft License fault as OEM licenses are bound exclusively to the original mainboard onto which they were first deployed.  An already activated system cannot be reactivated, meaning re-installation of the OS is the only resolution.  OEM licenses cannot be in-place upgraded to retail editions either.  Microsoft code expressly prevents these actions, and attempts to circumvent that mechanism violate numerous international laws including the DMCA in the USA, so Unitrends cannot develop products that facilitate this process.   

Some vendors may issue new keys under warranty if a board is replaced in the existing chassis, but using that new key requires OS re-installation, the existing key cannot be replaced with an alternate key on an already activated OEM installation. 

If an OEM server has crashed and recovery would be required to an alternate platform, Unitrends support can assist as necessary with application and file level recovery for customers who build and deploy a newly licensed operating system of compatible versions.  Unitrends can also assist in basic recovery of the OS image through BareMetal or Windows Replicas, however, some OEM configurations are hardware proprietary and will not boot without certain chips present while other systems may boot and remain unable to log in, and even if they do noot, they will violate licensing and prevent login until rectified.  Licencing issues for bootable servers would be left between the customer and 3rd party vendor to solve.  Microsoft itself will not approve OEM key re-issue itself and will direct customers to their vendor the system was purchased through.  Customers who purchased SA on their OEM servers within 90 days of original server purchase can request new keys from Microsoft to perform that reimage operation without needing to purchase that license.  

OEM licenses are not supported for use with Unitrends DRaaS services.  

Customers who have OEM systems deployed in their environment who are concerned they may need to one day in the future perform recovery to an alternate board or platform need to understand only file and application recovery would be supportable by Unitrends in those situations.  If critical systems are deployed using OEM keys, it may be in many customer's DR planning interests to deploy new licences on alternate systems and migrate their applications and data to retail keys that include transfer rights.  From a Disaster Recovery Best Practice standpoint, Unitrends and most other vendors recommend that OEM keys not be used on any servers in production where server recovery in full from Baremetal is expected.  


Recovery of a server or workstation leveraging an OEM License is supported in the following methods:

1) Recovery to the original motherboard the OS was prior deployed to.

  • This will function using traditional uBMR for supported Windows configurations as long as the mainboard has not been changed.
  • Contact Unitrends for assistance as needed.
    2) Attempt Baremetal Recovery and contact vendor for updated licensing as needed. 
    • Perform a uBMR or Windows Replica recovery of your OEM OS system.
      Unitrends will assist in this attempt as may be requested.
    • Inject necessary hardware NIC or storage drivers as may be necessary for uBMR restores
    • If system results in blue screen on boot 3 or more times, try to boot from Windows Repair media and correct issues (see hardware vendor for assistance)
    • If prompted with license activation prompts or non-genuine license warnings, contact Microsoft or your original OEM vendor for assistance.
    • If the system cannot safely boot due to OEM hardware dependencies, or, due to license restrictions, try method 3.
    3) Recovery of the OS to a VM platform or dissimilar hardware (steps are not necessarily to be completed in this exact order).  
    • Deploy a clean new OS image on the new hardware or VM and update it to the same or higher patch release vs the original, ensure OS this activates as necessary.  Preferably, to avoid confusion with prior backup schedules and historical data, deploy the system with a new DNS name and preferably a prior unused IP. 
    • Join the new server to Active Directory as may be necessary.  If this is an Active Directory server, relocate and FSMO roles as may be necessary.
    • Install and update any 3rd party applications necessary for the server to operate and enable any necessary Windows Roles/features.
    • Install the Unitrends Agent on the server and register the new asset to the Unitrends Appliance.
    • Leverage Unitrends UI to perform file/directory restoration of any user data.  Do not restore components of the Windows or Program Files directories unless you are certain they are data-only files (no not restore applications themselves as registry information would not be present to support them in a new deployed server)
    • Leverage Unitrends UI to perform SQL, Exchange, SharePoint Simple configurations
    • Leverage Unitrends FLR recovery for any SharePoint Farm or Oracle Database using 3rd party tools to facilitate database recovery.
    Recreate any network shares if necessary.  


    To ensure licencing issues are not unexpectedly encountered as part of a priority outage recovery effort, Unitrends provides numerous tools to assist customers and to test recovery, including CDM test automation technology in our enterprise plus license tiers.  Regardless of available automation features, customers are strongly encouraged to test recover every critical server periodically and document requirements and expectations as well as processes that may be needed to reconfigure applications post recovery.  Understand as well, some roles like cluster node servers or SharePoint Farm servers cannot be recovered directly via Baremetal due to OS/Application limitations imposed by Microsoft, and other systems like Active Directory should not be recovered in production if other ADDC servers remain available.  

    A note on Microsoft license transfer rights in general:  Many non-OEM OS editions from Microsoft that DO include transfer rights still strictly limit transfers to 1, 3, or 5 events in the lifetime of the issued key.  For this reason, Unitrends recommends that after any such DR process, customers validate their remaining transfer key count, and if they cannot confirm additional rights are available, replacement of the restored server with a new valid key should be pursued.  Future dissimilar restores of the same system may be prevented due to transfer rights limitations that may differ from one OS SKU to another, which are only clarified in the specific EULA for that sky and which may differ internationally or by release date of Windows.  Volume Licenses also have some limited transfer rights including prohibitions on "temporary" use (once moved it cannot be moved again for at least 90 days).   Unitrends and other DR product vendors cannot override or bypass these restrictions.   

    Application Transfer Rights:  3rd party applications themselves may in some cases also not be licensed for transfer.  Manufacturers use many methods of hardware ID tracking to detect when their applications have been moved, which may require additional licencing costs to run the restored application on new hardware.  This also cannot be bypassed by Unitrends.

    The term AD, ADDC, and Active Directory are used interchangeably.

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