When trying to update a Windows 10 or 11 install to Pro, by going to Start > Settings > System > Activation > Change product key, and entering a valid Windows Pro edition product key, you may get the below error:

The product key you entered didn't work. Check the product key and try again, or enter a different one. (0x80070057)

To get around this, you will need to use a Windows Generic Key first to upgrade it to Pro

1. The key for Windows 11 Pro is: VK7JG-NPHTM-C97JM-9MPGT-3V66T
   - Other versions can be found here: Windows 11 Generic Keys for All Editions (winaero.com)
2. Before entering this key, disconnect the device from the network
3. Then go to the Activation settings and Select Change Product Key
4. Enter the generic key from above and press OK. This will then prompt for an upgrade to Pro. Press OK
5. This will then reboot and once it has powered on again, it will be Windows 11 Pro
6. Now you need to reconnect it to the network and navigate to the activation settings, and select Change Product key.
7. Now enter the product key purchased by the customer. The device will now be activated correctly.