Active directory Use the common name when editing accounts through Active directory.
Users can logon to a Windows 2000 domain using two different logon names, see below. The point of the UPN is to consolidate the e-mail and logon namespaces so that the user need only remember a single name. Thus, a user can keep the same login name, even if the account is renamed or moved. The UPN is the preferred logon name for Windows 2000 users. UPN logon means more typing and is not mandatory.