1. Start Run “Dcpromo”  this will launch the Active Directory Domain Services Installation Wizard Click on Next on this page and the following page

2. On the “Choose a Deployment Configuration” page, Select the “Existing Forest “  option and below verify that  “Add a domain controller to an existing domain” option is selected (as shown below) Click on Next

3. On the “Network Credential” page Enter in a Domain Admin account Under “Alternate Credential”  Enter in password for the admin user. Click on Next

4. On “Select Site” select the site where the RODC will be placed Click on Next

5. On “Additional Domain Controller” page verify the option for Read-only Domain Controller(RODC) is selected Click Next

6.To use the default folders that are specified for the Active Directory database, the log files, and SYSVOL, click Next.

7. Type and then confirm a Directory Services Restore Mode password, and then click Next.

8. Confirm the information that appears on the Summary page, and then click Next to start the AD DS installation. You can select the Reboot on completion check box to make the rest of the installation complete automatically.

Reference:

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