Hello Mark,
Thank you for sharing the details about your activation issue I appreciate the effort you put into explaining the situation. I completely understand how frustrating it is to have a valid Windows 11 Pro license suddenly stop working especially when you’ve invested in it and can’t seem to reach anyone at Microsoft for help.
Experiencing hardware problems like a motherboard or GPU failure and then running into activation errors can feel overwhelming you shouldn’t have to pay again when you have proof of purchase from a trusted retailer.
When major hardware changes occur such as replacing the motherboard Windows often interprets this as a new device and may disable activation until it’s reverified. The system needs to confirm that your license is linked to your Microsoft account and that this is the same PC after the hardware change. You’ve already taken the right step by using the Activation Troubleshooter and selecting the option for hardware changes. The next thing to check is whether your Windows license is linked to your Microsoft account. In Settings select System select Activation it should say “activated with a digital license linked to your Microsoft account.” If it’s not linked sign in with your Microsoft account as an administrator and then run the Activation Troubleshooter again choosing the hardware change option and confirming “This is the device I’m using now.”
If activation still doesn’t work try entering your Windows 11 Pro product key manually under Settings select System select Activation select Change product key, especially if your key is retail and transferable. Keep in mind that OEM keys may not transfer and could be tied to your original motherboard.
Could you confirm whether your license is retail or OEM and let me know if you’ve tried re-entering the key manually after the hardware swap?
I hope this answer is helpful if you have further questions feel free to reply back
Regards,
Marcelo