To Host Website(Virtual Directory) using a "A share located on another Completer"
in II6. You need to use valid credentials in the "Connect As" window.
If you are implementing Single Sign-On, You need to keep the default checkbox in the "Connect As" without giving
any credentials and use "Integrated Windows Authentication" in "Directory Security" for the website.
Keep the "Anonymous Access" checked, change the anonymous user credentials to valid admin credentials having access