Error when you try to install the Azure Active Directory Sync Tool: The computer must be joined to a domain

Original product version:   Cloud Services (Web roles/Worker roles), Azure Active Directory, Microsoft Intune, Azure Backup, Office 365 Identity Management
Original KB number:   2419250

Symptoms

When you try to install the Microsoft Azure Active Directory Sync Tool, you may receive the following error message:

The computer must be joined to a domain.

Cause

This issue may occur if the computer isn't joined to an Active Directory Domain Services (AD DS) domain or if the computer doesn't register a host (A) resource record with its Domain Name System (DNS).

Resolution

To resolve this issue, use one of the following methods.

Method 1: Computer isn't joined to an AD DS domain

Join the computer to an AD DS domain. To do this, follow these steps:

  1. On the computer that you want to join to a domain, select Start, select Control Panel, and then double-click System.
  2. Under Computer name, domain, and workgroup settings, select Change settings.
  3. On the Computer Name tab, select Change.
  4. Under Member of, select Domain, type the name of the domain that this computer will join, and then select OK.
  5. Select OK, and then restart the computer.

Method 2: Computer is already joined to an AD DS domain

If the computer is already joined to an AD DS domain, make sure that the computer's DNS settings are correct and that a host (A) resource record for the computer is registered with DNS. To do this, follow these steps:

  1. Open Network Connections.

  2. Right-click the network connection that you want to set up, and then select Properties.

  3. Do one of the following, as appropriate for the connection that you want to set up:

    • For a local area connection: On the General tab, select Internet Protocol (TCP/IP), and then select Properties.
    • For all other connections: On the Networking tab, select Internet Protocol (TCP/IP), and then select Properties.
  4. If you want to obtain DNS server addresses from a Dynamic Host Configuration Protocol (DHCP) server, select Obtain DNS server address automatically.

  5. If you want to configure DNS server addresses manually, select Use the following DNS server addresses. In the Preferred DNS server box, type the IP addresses of the preferred DNS server. In the Alternate DNS server box, type the IP addresses of the alternative DNS server.

  6. Select OK two times, and then close Network Connections.

  7. At a command prompt, type the following commands, and press ENTER after each command:

    ipconfig /flushdns
    
    ipconfig /registerdns
    
  8. If the issue isn't resolved, restart the computer that has Directory Sync Tool installed.

  9. If the issue still isn't resolved, make sure that the computer that has the Directory Sync Tool is installed can communicate with the computer that's running AD DS.

More information

Still need help? Go to Microsoft Community or the Azure Active Directory Forums website.