From a quick search on the internet it appears that the domain controller just refers to a Windows NT or 2000 Server that is on the network. This can be any server running the required software. If you have an IS/IT department you have a domain controller. It also appears to require Windows 2000 or Server based on the number of users you require. Here is the release note I found that referenced the Domain Controller: RSViewSE release notes I would contact Rockwell or your local rep for more detailed information.