The following guide will step you through the basic setup of Active Directory on Windows Server 2008.
[_] Fully Installed and Configured Windows Server 2008
[_] Windows Server 2008 installation media may be needed
[_] Static IP address for target network(requested but not required)
1. Navigate to Start->Administrative Tools->Role Manager
2. Select 'Add Roles' to start the Wizard
3. Select [Next] at the Begin screen
4. Select 'Active Directory Domain Services', then click [Next]
5. Read the ADDS message then click [Next]
6. When you get to the Installation screen, click [Install]
7. After the install verify that it says 'Installation succeeded' and click [Close]
8. You should now be back at the Roles selection screen
9. Now run "dcpromo.exe" from the 'Run' command within 'Start'
10. After executing the command you should see the below, then click [Next]
11. On the ''Operating System Compatibility'' popup click [Next]
12. If this is a new forest select "Create a new domain in a new forest", and click [Next]
13. Enter a Fully Qualified Domain Name, then click [Next]
14. Your system will start processing your request
15. If no other Domain Services servers exist set the 'Function Level' to "Windows Server 2008", and click [Next]
16. On the "Additional Domain Controller Options", verify that 'DNS server' is selected and click [Next]
17. You will receive a popup warning click [Yes] to continue, this warning is expected
18. On the "Location for Database", make any changes you might need, and then click [Next]
19. On the Directory Services screen enter a password for the DS server, then click [Next]
20. On the Summary screen click [Next]
21. Your system will now start the installation process, give it a little bit of time to complete.
22. When it is complete you will see the following graphic, click [Finish]
23. You will then be asked to restart, do so, then log back in.
24. You will now have a functional Windows 2008 Active Directory Server. Select Start->Administrative Tools->Active Directory Users and Computers to view your AD system.
Microsofts Active Directory product is currently the top system for providing network domain logins. A similar system is now offered by Linux called Samba 4, it will provide basic AD services based on Windows Server 2000.
Once you've accessed your AD you can add additional OU's, computers, and users as needed.