We are upgrading our NT domain to Active Directory. This domain is required to be a part of an existing forest. After we upgrade the domain controller to Windows 2003, we would need to install the Active Directory Connector. Because there are numerous Windows NT BDCs, it would not be possible to upgrade them all at once and convert this domain to Native Mode immediately. However, we are unable to install the ADC. ADC requires an account that is a Domain Administrator, Schema Administrator and Enterprise Administrator. I tried using an Enterprise/Schema Administrator account for ADC, but it gave me an error that the account needed to be local to the domain. I then tried to create an ADC service account in the domain in question, but I am unable to add it to the Enterprise/Schema Admins groups. When I add the account, it says because the account comes from a Mixed Mode domain, it will not work. So I can't add the account directly to these groups, and I don't see a way of nesting the account in a group that is part of Enterprise/Schema Admins. Is there a way to make the ADC work? If it is not possible, what will be the drawback to running without the ADC until the domain can be converted to Native Mode?