From the point of view of administration, computer network can be of two types: equivalent/homogeneous and centralized. Homogeneous network has small dimensions and, as a rule, is used by not very big organizations or in home conditions. Centralized net-work is applied in large organizations/companies and as software support – use special program package. Directory service “Active Directory” is considered to be one of the special program packages. It shows network in its virtual logical and physical representations, which are administrated by means of special servers – domain controllers. In this way centralized computer network, derived in this way, is named domain.