0xC004C003, Activation server determined the product key is blocked
How to Know Why Your Windows 10 Was Not Activated
0xC004C003, Activation server determined the product key is blocked
KB5001692: Windows Activation fails with error 0xc004c003 on devices which have installed the Windows 10 January 2021 nonsecurity preview release or a later version - Microsoft Support
Activation Error: 0xC004C003 after upgrading to Windows 10 from - Microsoft Community
Windows Activation Error 0xc004c003, 0xC004C060, 0x803f7001, 0x800704cF, 0xC004F212, 0xC004F034 : Electronic First