Why am I not able to add a new computer to Active Directory?

Verify that the computer meets the system requirements for joining Active Directory.
Verify that the computer is on the same network as the domain-joined computers.
Check that the computer account is not already configured on the domain.
Verify that the computer’s IP address is up-to-date and able to locate the domain’s DNS server.
Verify that the user account has the necessary permissions to add computers to the domain.
Verify that the computer is up-to-date with its operating system patches and security updates.