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IT // Adventures

Windows 10 Activation After a Hardware Change

2 min read
Contents

Free Windows 10 upgrades are no longer activated with the product keys known from the past, but with a “digital entitlement” (quote Microsoft).

In my experience, this “digital entitlement” is made up of one or more hardware characteristics of a PC (aka “hardware ID”). During the upgrade process, this ID is sent to the Microsoft activation servers and stored there, so that Windows 10 can later be activated “easily” without user interaction (e.g. after a reinstall).

Problem

The problems start at the latest when parts of the hardware1 have to be replaced because of a defect. If the hardware ID changes during the replacement, the Microsoft activation server refuses to recognize the Windows 10 installation as “activated”. In this case, the error details of the activation wizard should show “This product key didn’t work. (0xC004C003)”.

Wait a moment - “product key”? Since Microsoft still requires product keys for activation under other licensing models (MSDN, volume license, etc.), a generic “upgrade key” is installed during the Windows 10 upgrade. It (presumably) instructs the Microsoft activation servers to activate based on the hardware ID, provided that the previously installed Windows version was already activated correctly.

In the end, a changed hardware ID means that the Microsoft activation servers no longer recognize the installation as “already activated” and prevent a new activation.

Solution according to the MS support hotline

The staff at the MS support hotline recommend reinstalling the Windows version that was installed before the upgrade, activating it, and then running the upgrade to Windows 10 again.

Solution (workaround)

The Windows 10 November Update (aka “Windows 10 1511”) can officially be installed during setup with the product key of a (qualifying) previous version. What is less well known, however, is that this also works afterwards via the activation wizard.

So, for a Windows 10 RTM with the above error message during activation…

  1. upgrade to Windows 10 1511
  2. open the activation wizard and click “Change product key”
  3. enter the key of the Windows version that was installed before the upgrade and perform the activation

Sources

Footnotes

  1. Presumably(!) only the CPU and mainboard are affected. ↩