Installing Active Directory

One of the major improvements between Windows 2000 and Windows NT 4 is the fact that the decision on whether or not a server becomes a domain controller is made independent of the actual OS installation. As such, turning a member server into a domain controller (or vice-versa) is something that can be done without needing a complete reinstallation. The tool used to install (or uninstall) Active Directory on a server is the Active Directory Installation Wizard, dcpromo.exe. The section takes a look at the various decisions to be made throughout the wizard.

Before getting started, there are a few important requirements that you need to be aware of, as listed below:

  • The system must be running Windows 2000 Server, Advanced Server, or Datacenter Server
  • AD installation requires a minimum of 200 MB disk space for the AD database, and 50 MB for the transaction log files. These can be placed on FAT. FAT32, or NTFS partitions
  • The server must have at least one NTFS partition, to house the SYSVOL folder.
  • TCP/IP installed and configured to use DNS is required
  • Appropriate administrative privileges are required.

The Active Directory installation wizard can be used for a few different purposes, and you should be aware of the reasons. These include creating a new forest (a new root domain), adding a domain controller to an existing domain, creating a new tree, and creating a new child domain. It is very important to pay attention during the wizard to ensure that you are making the correct choices, especially when creating the root domain of the forest, since this cannot be renamed for example. For the purpose of this article, I will cover the installation of a new root domain. You should familiarize yourself with the other options, however.

Author: Dan DiNicolo

Dan DiNicolo is a freelance author, consultant, trainer, and the managing editor of He is the author of the CCNA Study Guide found on this site, as well as many books including the PC Magazine titles Windows XP Security Solutions and Windows Vista Security Solutions. Click here to contact Dan.