The end-user has tried to use Windows 7 and 8 activation keys.The activation key has been blocked due to the hard drive being cloned.The most common causes of WINDOWS 10 ACTIVATION ERROR OXC004C003 is as follows. SOLUTIONS FOR FIXING WINDOWS 10 ACTIVATION ERROR 0XC004C003ĬAUSES OF THE WINDOWS 10 ACTIVATION ERROR 0XC004C003.CAUSES OF THE WINDOWS 10 ACTIVATION ERROR 0XC004C003.