Why can't I select the domain name extension that I want?

Published: April 26, 2010

Updated: March 30, 2011

Applies To: Windows Small Business Server 2011 Essentials

When you choose a domain name for your Internet Web site, you also need to specify the domain name extension that you want to use. The extension is identified by the letters that follow the final period of any domain name. (The formal term for the extension is the “top-level domain” or “TLD.”)

There are two main types of domain extensions that you can use: generic and country-code.

Generic top-level domains

Generic domain extensions are three or more letters in length, and they are typically used by certain types of organizations.

Examples of Generic Top-Level Domains


Domain Extension Description


Typically used by commercial organizations, but it can be used by anyone.


Designed for businesses that offer network infrastructure services.


Originally used by non-profit agencies and other business that did not fall into another generic top-level domain category. Can be used by anyone.


Restricted to use by educational organizations.

Country-code top-level domains

These domain extensions are two letters in length. They are designed to be used by organizations in the country or region that is associated with that code. Some country-code top-level domains are restricted for use by citizens of that country or region. Others are available for use by anyone.

Examples of Country-Code Top-Level Domains


Domain Extension Description


For use by Web sites in Canada.


For use by Web sites in China.


For use by Web sites in Germany.


For use by Web sites in the United Kingdom.

To view the full list of top-level domains, see the Internet Assigned Numbers Authority Web site (http://go.microsoft.com/fwlink/?LinkId=117438).

What to do if a domain extension is not available to select in the Set Up Domain Name wizard

When you run the Set Up Domain Name Wizard, the wizard looks at your system information to determine your country or region. The wizard then displays only those domain extensions that the participating providers in your area support. If the domain extension that you want does not appear in the list, you must choose a different domain extension to continue. Select an extension from the list that the wizard returned.