| Active Directory
Active Directory stores information about network objects — such as user accounts and shared printers — and provides access to that information. To make this server a domain controller, you must install Active Directory. domain controller In a Windows 2000 Server domain, a computer running Windows 2000 Server that manages user access to a network, which includes logging on, authentication, and access to the directory and shared resources.

The Active Directory Installation wizard configures this server as a domain controller and sets up DNS if it is not already available on the network. Use this wizard for the following scenarios:

- No existing domain controller — sets up your server as the first domain controller on the network.
- Domain controller already on network — sets up your server as an additional domain controller, new child domain, new domain tree, or new forest.

additional domain controller
Any Windows 2000 domain controller installed into an existing domain. All domain controllers participate equally in Active Directory replication but, by default, the first domain controller installed in a domain is assigned ownership of at least three floating single master operations. Additional domain controllers installed into an existing domain do not assume ownership of these operations by default. See also floating single-master operation (FSMO).
child domain
A domain located in the namespace tree directly beneath another domain name (the parent domain). For example, "example.microsoft.com" would be a child domain of the parent domain, "microsoft.com." Also known as subdomain.
domain tree
The hierarchical tree structure that is used to index domain names. Domain trees are similar in purpose and concept to directory trees, which are used by computer filing systems for disk storage. For example, when numerous files are stored on disk, directories can be used to organize the files into logical collections. When a domain tree has one or more branches, each branch can organize domain names used in the namespace into logical collections.
forest
A set of one or more trees that do not form a contiguous namespace. All trees in a forest share a common schema, configuration, and global catalog. The trees must trust each other through transitive, bidirectional trust relationships. Unlike a tree, a forest does not need a distinct name. A forest exists as a set of cross-reference objects and trust relationships known to the member trees. Trees in a forest form a hierarchy for the purposes of trust.

Important
You need a partition formatted with the version of NTFS used in Windows 2000 to host Active Directory.

Caution
Be sure you are familiar with Active Directory and how it will affect this server before you proceed.

| Learn more about Active Directory and domain controllers to determine whether you need to set up Active Directory.

Start the Active Directory wizard

After you finish with the wizard, your server will restart and the Configure Server screen will appear. Return to the Active Directory screen to manage your computer and user accounts.