Windows 11 Pro activation issues

Clive 0 Reputation points
2026-11-11T16:54:07.7566667+00:00

I purchased a copy of Win 10 Pro back in 23/24, which I upgraded to 11 through MS updates. However, of late I have been suffering random PC crashes and with all the install/uninstalls since I built the PC I decided to do a full clean Install. I created the ISO with Windows Media Creation for Win 11 Pro and Rufus so that I could remove bloat ware and unnecessary privacy intrusions. This worked great and the install went really smooth (and before I reinstalled I went and grabbed a copy of my the Windows key via regedit).

The problem comes with activation as I've tried several routes but still nothing.

  1. Settings > System > Activation
    We can't activate Windows on this device because you don't have a valid digital licence or product key. if you think you have a valid licence or key, select Troubleshoot below. Error Code: 0x803FA067
  2. Product Portal Activation.
    I got my installation ID from cmd but when I input this into the portal I get a "sorry, your installation ID was unable to be validated."
  3. My last resort was customer support and the wonder of the AI assistant which just had me running around circles and repeating 1 & 2.

I know it's very likely something I've done but any advice to get me out of this hole would be appreciated.

Windows for home | Windows 11 | Licensing and activation

2 answers

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  1. Shemuel Gopichund 0 Reputation points
    2026-11-12T04:16:55.24+00:00

    Use a dummy activation key in offline mode. then activate with the activation key once back online

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  2. Matthew J. Moore 85 Reputation points
    2026-11-12T04:11:01.19+00:00

    Rufus is likely causing issues. By checking the box to skip the Microsoft account in Rufus, the local account is created and Windows can't look up the digital licence linked to your MS account in the previous installation. Try logging into windows using the same Microsoft account (Settings > Accounts > Your info > Sign in with a Microsoft account instead), leave for a few minutes then return to activation and click Troubleshoot. If it still doesn't work, you should see a link that says “I changed hardware on this device recently”. Select your PC from the list. This should work.

    The phone portal won't work because the installation ID is created from the dummy key Windows created. This only works once you have installed the real key.

    If you have the email or receipt from when you bought pro, the real key should be in there. Just enter this in using activation > Change product key and it should work.

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