When visiting intranet sites, you may be repeatedly prompted for credentials (your user name and password) as a result of ...

When visiting intranet sites, you may be repeatedly prompted for credentials (your user name and password) as a result of the enhanced security configuration. In the past, Internet Explorer automatically passed your credentials to intranet sites. The enhanced security configuration disables the automatic detection of intranet sites. If you want your credentials to be passed automatically to certain intranet sites, add those sites to the Local intranet zone. For more information, see Add sites to the Local intranet zone.

Do not add Internet sites to the Local intranet zone, because your credentials will be passed automatically to the site if they are requested.