In the Tool menu, go to Internet Options > Security.
Choose Local Intranet, and then click Site.
Mark the “Automatically detect intra network” checkbox, and then click Advanced.
Add the OpenSSO Enterprise URL to the Websites list if the URL is not already on the list.
For pre-6.0 Internet Explorer versions, be sure the Identity Server is in the browser's intranet zone and that native Windows Authentication is enabled. For more information, see Enabling Windows Authentication.