If the name of the server where you plan to install Active Directory Domain Services (AD DS) does not conform to Domain Name System (DNS) specifications, the Active Directory Domain Services Installation Wizard displays a warning. The warning states that you must rename the server or, if you retain the nonconforming name, that you must use a Microsoft DNS server so that clients can locate the server. However, the warning does not prevent you from installing AD DS successfully on this server to make it a domain controller. You can continue to install AD DS on this server and then correct its DNS configuration after the installation is complete.

For this domain controller to be discovered by other domain members and domain controllers, the DC Locator DNS records must be added to DNS. It is strongly recommended that your DNS infrastructure allow dynamic updates of DC Locator DNS records. However, your DNS administrator may add these records manually after the installation is complete and the domain controller is restarted. These records are listed in the following location:


You will receive the warning for a nonconforming DNS name if the name of the server contains one or more of the following invalid characters:

{ | } ~ [ \ ] ^ ' : ; < = > ? @ ! " # $ ^ ` ( ) + / , * or a space

Valid characters for a computer name include all uppercase letters (A through Z), lowercase letters (a through z), numbers (0 through 9), and hyphens (-).

To resolve this problem, exit the wizard, rename the computer, and then restart the wizard.

Renaming your computer

You can use the following procedure to rename your computer.

Membership in the local Administrators group, or equivalent, is the minimum required to complete this procedure. Review details about using the appropriate accounts and group memberships at http://go.microsoft.com/fwlink/?LinkId=83477.

To rename your computer
  1. Click Start, right-click Computer, and then click Properties.

  2. Under Computer name, domain, and workgroup settings, click Change settings.

  3. On the Computer name tab, click Change.

  4. In Computer name, type the new name for the computer, and then click OK.

  5. When you are prompted, restart your computer.

Additional considerations

  • A computer joining a domain must use the name that was created for it by the network administrator, unless you have a user name and password with rights to create computer accounts.

  • If you supply a valid user name and password for a domain, the domain membership will be updated automatically with the new computer name.

  • Computer names that are 15 characters or less are recommended. If your computer has TCP/IP installed, the computer name can be up to 63 characters long. However, it should contain only the numbers 0 through 9, the letters A through Z and a through z, and hyphens. You may use other characters, but doing so may prevent other users from finding your computer on the network. If your network is using a Microsoft DNS server, you can use any characters except periods. If other networking protocols are installed without TCP/IP, the name is limited to 15 characters.

    Before you use additional characters, consider the following issues:

    • Some non-Microsoft resolver software supports only the characters that are listed in Request for Comments (RFC) 1123. If you have any non-Microsoft resolver software, that software is probably not able to look up computers with names that have nonstandard characters.

    • A DNS server that does not support UTF-8 encoding might accept a zone transfer of a zone containing UTF-8 names, but it cannot write back those names to a zone file or reload those names from a zone file. Therefore, you must not transfer a zone that contains UTF-8 characters to a DNS server that does not support them.

  • If you specify a computer name that is longer than 15 characters and you want longer names to be recognized by the Active Directory domain, the domain administrator must enable registration of DNS names that are 16 bytes or longer.

  • If your computer is a member of a workgroup, no networking is installed (or TCP/IP is not installed), the computer name cannot be more than 15 characters, and the characters must all be uppercase.