When installing Windows NT Server, you can specify that the server be a member of a Workgroup or a Domain, or you can set the computer to be a domain controller. For the installation to be completely unattended, you must supply this information in the answer file.
The answer file entries for adding a server to a Workgroup or Domain are the same as those for workstations. To set the computer to be a domain controller, add the entry described under "Installing a Domain Controller" and "Setting the Server Role" in Appendix A, "Answer Files and UDFs" of the Windows NT Workstation 4.0 Resource Guide.