Every person who has access to the network requires a user account. A user account makes it possible to do the following:
Authenticate the identity of the person connecting to the network
Control access to domain resources
Audit actions performed using the account
Windows Server 2008 creates only two normal predefined accounts on a domain controller: the Administrator account, which is granted all rights and permissions, and the Guest account, which has limited rights. On domain controllers there is also a KRBTGT key distribution account, and on non-DCs there are built in special accounts for Help and Support and Remote Assistance. All other accounts are created by an administrator and are either domain accounts, which are valid ...