How to validate the OEM activation key in Windows 10

This article introduces how to validate the OEM activation key in Windows 10.

Applies to:   Windows 10 - all editions
Original KB number:   4346763


Starting at Windows 10 Creators Update (build 1703), Windows activation behavior has changed. The unique OA3 Digital Product Key (DPK) isn't always presented as the currently installed key in the device. Instead, the system behaves as follows:

  • Windows 10 (including all versions starting at Windows 10 Creators Update) is deployed to a device by having the appropriate default product key. You can run slmgr /dli or slmgr /dlv to show the partial default product key instead of the OA3 DPK as the current license in the firmware. The product ID displayed on the Settings > System > About page isn't unique for the Windows 10 key that's being used.

  • A device that's running any Windows 10 OEM client edition, such as Windows Home or Windows Professional, and is activated by using the OA3 DPK in the firmware is upgraded to a newer version. For example, it's upgraded from build 1703 to build 1709. However, sometimes running slmgr /dli or slmgr /dlv doesn't show the OA3 DPK as the current license. Instead, these commands show the default product key.

The behavior is by design. The activation and user experience aren't affected. But OA validation in the factory may be affected as follows:

  • The output of the slmgr /dlv or slmgr /dli command isn't necessarily the last five (5) digits of the injected DPK. So you can no longer rely upon these commands to return the expected results.

Recommendations for validating the product ID against the product key ID of OA3 DPK

Every OEM has a different manufacturing process that has been adopted through years of experience. Specifically, to validate the DPK against the installed Windows 10 edition, we recommend that you don't rely on the output of slmgr /dlv or slmgr/dli. Instead, use the latest OA3Tool as follows:

  • OA3TOOL /Validate

    It runs a validation pass to make sure that:

    • the MSDM table exists.
    • the MSDM table header includes all the required fields.
    • the MSDM table entries exist and comply with the correct formats.
  • OA3TOOL /CheckEdition

    Does a cross-check between the injected DPK and the target Windows edition if they match.

The Windows activation system is designed to use the product key that's injected into the firmware of the computer during manufacturing. It automatically activates the device when the device first comes online. This operation is used daily on thousands of devices. As an extra check, OEMs are encouraged to run the complete end-to-end validation process, including activation on a subset of the devices, to validate the user experience with their PCs. If you experience any issues, engage with us through the usual channels.

Why did Microsoft remove the ability to check the last five digits of the product by using slmgr

SLMGR is a legacy tool. Although we haven't updated slmgr, and because of updates in successive system builds, the last five digits of the product key that are shown by slmgr /dlv or /dli don't match the product key injected into the system BIOS. It's by design. We have no intentions of validating SLMGR for every Windows 10 release or making any other changes. We are very open to feedback regarding the OA3 tool and more capabilities we can add to it to improve the manufacturing flow.