Stubborn Windows activation failing on clean install for OEM computer

Check activation status:

slmgr /xpr

Retrieve the product activation code from the UEFI motherboard:

wmic path softwarelicensingservice get OA3xOriginalProductKey

Use the retrieved key to activate: (replace with a valid key)

slmgr //b /ipk XXXXX-XXXXX-XXXXX-XXXXX-XXXXX

Online Activation:

slmgr /ato

Check activation status:

slmgr /xpr