Sample Web.config file for a WCF service - with Baisc Authentication enabled in IIS

<?xml version="1.0" encoding="UTF-8"?>
<configuration>

  <system.web>
    <compilation debug="true" targetFramework="4.0" />
  </system.web>
  <system.serviceModel>
    <bindings>
      <basicHttpBinding>
        <binding name="BasicHttpEndpointBinding">
          <security mode="TransportCredentialOnly">
            <transport clientCredentialType="Basic" />
          </security>
        </binding>
      </basicHttpBinding>
    </bindings>
    <services>
      <service behaviorConfiguration="WcfServerTest.Service1" name="WcfServerTest.Service1">
        <endpoint address="" binding="basicHttpBinding" bindingConfiguration="BasicHttpEndpointBinding" name="BasicHttpEndpoint" contract="WcfServerTest.IService1">
          <identity>
            <dns value="localhost" />
          </identity>
        </endpoint>
      </service>
    </services>
    <behaviors>
      <serviceBehaviors>
        <behavior name="WcfServerTest.Service1">
          <!-- To avoid disclosing metadata information, set the value below
               to false and remove the metadata endpoint above before deployment -->
          <serviceMetadata httpGetEnabled="true" />
          <!-- To receive exception details in faults for debugging purposes, set the value below
              to true. Set to false before deployment to avoid disclosing exception information -->
          <serviceDebug includeExceptionDetailInFaults="false" />
        </behavior>
      </serviceBehaviors>
    </behaviors>
  </system.serviceModel>

  <system.webServer>
    <modules runAllManagedModulesForAllRequests="true" />
    <security>
      <authentication>
        <anonymousAuthentication enabled="false" />
        <windowsAuthentication enabled="false" />
      </authentication>
    </security>
  </system.webServer>

</configuration>