1) To configure Basic Authentication in Internet Information Services (IIS) 7, open Internet Information Services (IIS) Manager and select the site you want to manage. In Features View, double-click Authentication.
2) On the Authentication page, select Basic Authentication. In the Actions pane, click Enable to use Basic authentication with the default settings. Click edit to type the default domain and realm.
3) In the Edit Basic Authentication Settings dialog box, in the Default domain text box, type a default domain or leave it blank. Users who do not provide a domain when they log on to your site are authenticated against this domain.
In the Realm text box, type a realm or leave it blank. In general, you can use the same value for the realm name as you used for the default domain. f you enter the default domain name in the Realm text box, your internal Microsoft Windows domain name may be exposed to external users during the user name and password challenge.