The account %1 cannot be converted to be a domain controller account as its object class attribute in the directory is not ...

The account %1 cannot be converted to be a domain controller account as its object class attribute in the directory is not computer or is not derived from computer. If this is caused by an attempt to install a pre Windows 2000 domain controller in a Windows 2000 domain or later, then you should pre-create the account for the domain controller with the correct object class.