How to Add a Domain Controller to an Existing Domain (Server Manager)

As an IT Pro, it is highly likely that you’ve needed to add additional domain controllers (DCs) to your Active Directory environment. In this guide, we’ll demonstrate how to add a domain controller to an existing domain.

This article applies to: Windows Server 2016, Windows Server 2019, Windows Server 2022, and Windows Server 2025.

How to add a new domain controller to an existing domain

There are several reasons you may want to add a new domain controller to an existing domain: Adding redundancy, migrating a DC from old hardware to a fresh new server, etc. I’ll take you through those different steps first.

Initial configuration

I’ve built a new Windows Server 2022 Datacenter server (WS22-DC4) and added it to my domain – reinders.local.

Here, the only prerequisites are that you need to have an existing domain with domain controllers. I know… but I wanted it stated for completeness. If you are not sure how to add a server to a domain, check out How to Add Computers to a Domain Using PowerShell on Petri.com.

Installation

• The first step we’ll do is click the Start button, then click on Server Manager, then click the ‘(2) Add roles and features‘ link.

You can click Next three times to move through the introductory screens and choose the option to make changes to the local server.

• On the screen that follows, put a checkmark in the 2nd option above – Active Directory Domain Services (AD DS).
• When the second pop-up opens, you can click ‘Add Features’ and then click Next.
• On the ‘Select features‘ screen, click Next.

Click Next again and you’ll reach the ‘Confirm installation selections‘ screen. Go ahead and click the Install button!

• We can watch the lovely Installation progress and click Close when it’s over.

Configuration

• Click the yellow warning symbol in the upper-right corner, and you’ll see we have a ‘Post-deployment Configuration‘ process to go through.
• Click the ‘Promote this server to a domain controller‘ link.

The AD DS Configuration Wizard will then open.

When the Active Directory Domain Services Configuration Wizard was launched, it performed a few quick queries to our environment. The wizard discovered that this server is a member server in the ‘reinders.local’ domain. It assumes we want to promote this server as another domain controller. Because this is the scenario we are describing, we can proceed.

• Click Next to continue.

• I chose the location of this new DC to be in my ‘Reinders-HQ’ site from the dropdown and entered my Directory Services Restore Mode (DSRM) password.
• I then clicked Next.

• On the DNS Options screen, we’ll see a warning that a delegation for this DNS server cannot be created. By default, this is very common and can be ignored. Click Next.

• On the Additional Options screen, we should be able to keep the defaults and click Next.

• Here on the Paths screen, in a more robust environment, you would want to place the Database folder, the Log files folder, and the SYSVOL folder on separate physical volumes/disks. For our demo purposes, I’ll keep the defaults and click Next.

We’re almost there – don’t worry…on the Review Options screen, you can examine the selections, use the scroll bar to view all the info, and even view the PowerShell script the wizard will run in the background.

This opens a lot of potential for more automated and robust scripting if you happen to be on a team of engineers responsible for adding dozens or even hundreds of domain controllers in your enterprise environment.

• Back in our wizard, click Next, and we’re at the Prerequisites Check screen. Everything passed so click Install.

Here is a progress screen…

• And, we’re done, and a forced reboot is imminent…

After the reboot, the login screen is different. By default, it is ready for me to log in as the Domain Administrator for my reinders.local domain (REINDERS).

I logged in, opened Active Directory Users and Computers from the Administrative Tools menu, and clicked on the ‘Domain Controllers‘ folder in AD. There we go!

WS22-DC4 is now officially a domain controller.