PC crashes after Windows 11 Pro upgrade.

Retail: it can be transferred to a new device (even if the motherboard is replaced), and it is more flexible to bind Microsoft accounts. 

OEM version: It is bound to the motherboard of the original equipment and cannot be transferred (usually pre-installed systems or keys purchased from third-party channels belong to this category). 

Your upgrade was purchased directly from the Microsoft store, which is probably a retail version, but further verification is needed: 

I. Try to activate the Pro version directly on the new computer. 

If the new computer has Windows 11 Home installed, you can try to upgrade with the original Pro key: 

Open Settings → System → Activation → Change Product Key. 

Enter the Windows 11 Pro key you purchased. 

The system will automatically upgrade to the Pro version and activate it (online verification is required). 

II. associate a license through a Microsoft account 

If the key cannot be activated directly: 

Log in to the Microsoft account used at the time of purchase on the new computer (it must be consistent with the time of purchase). 

Go to Settings → System → Activation → Troubleshooting → "Recently changed hardware". 

Select the old equipment (damaged computer) and mark it as "no longer used". 

Select the current new device and bind the license. 

III. Replacement equipment activation: 

Replacing a computer belongs to replacing hardware. In this case, it may be necessary to follow the relevant steps: 

Reactivating Windows after a hardware change - Microsoft Support

Please allow me to explain that the Microsoft community support personnel do not have the authority and method to directly operate the activation status of Windows, and we can only provide a reference activation method. If none of the above schemes can help you activate Windows, you can directly contact the Microsoft online support personnel with activation authority: 

Go to the following website: Contact - Microsoft Support.   

Enter your Windows activation.  

Click on Get Help.  

Click on Contact Support.  

Select the windows.  

Click on Provide your phone number and a support agent will call you.  

Thank you for your understanding and cooperation! If you have any other questions, please feel free to contact us.