Introduction
In this blog post, we will learn how to install the Active Directory Domain Services role and then promote the server to domain controller on Windows Server 2019.
What is Active Directory Domain Services
Active Directory Domain Services, also known as ADDS or simply Active Directory, is a directory service that stores information about users, computers, and other devices on the network and makes it easy for administrators and users to find that information.
Active Directory is one of the most important features of Windows Server, which distinguishes it from other enterprise-level server operating systems.
Install Active Directory Domain Services
To install Active Directory Domain Services, login as an administrator.
1. Click on start and open the Server Manager.

2. Click Manager, and then click Add Roles and Features.

3. On the before you begin page, click Next.

4. Choose Role-based or feature-based installation and click Next.

5. Select destination server and click Next.

6. Select the checkbox of Active Directory Domain Services and click Next.

7. Click Add Features.

8. On the select server roles page, click Next.

9. On the Add Roles and Features wizard page, click on Next.

10. Again, click on Next.

11. At the confirm installation selections, click Install and wait for the installation process to complete.

12. The Active Directory Domain Services role installation has been completed, click Close.

Promote server to Domain Controller
After installing Active Directory Domain Services roles, the next step is to promote a server to the domain controller.
1. Open the Server Manager. Click the yellow warning mark and then click Promote this server to a domain controller.

2. Select Add a new forest. Fill in the root domain name. Click Next.
For example we will use root domain name easytechhub.com.

3. On the Domain Controller Options, leave the default settings and type in the Directory Service Restore Mode password and click Next.

4. On the DNS options page, ignore the warning, leave the default settings, and click Next.

5. Click Next after leaving the default NetBIOS domain name.

6. Leave the paths as default and click on Next.

7. Review your selections before executing. You can click View script to see the Windows PowerShell script for automating the installation.

8. All prerequisite checks passed successfully. Click Install and wait for the installation process to complete.

After the installation is completed, the server will reboot automatically, and you can login to the domain with your credentials.
Follow our post below on how to add a Windows Server to a domain network.
https://easytechhub.com/how-to-add-a-server-to-a-domain-network/
Conclusion
Active Directory Domain Services is a directory service that stores information about users and other objects and make this information available to administrators and users.