Hi Ian, I completely understand how frustrating this must be you’ve already gone through the hassle of upgrading your hardware because Windows 11 didn’t support your old CPU and now you’re stuck in an endless loop just trying to reactivate something you already paid for
If Windows won’t reactivate after your hardware upgrade first check if your license is Retail or OEM. Then try the Activation Troubleshooter in Settings and select I changed hardware recently. If that fails reenter your product key reset activation using PowerShell commands or contact Microsoft Support to manually reset your activation limit.
Have you already linked your Windows license to your Microsoft account before the hardware change or was it only activated locally on the old PC?
Best regards
Lucky Charm