Enabling Anonymous Authentication (IIS 6.0)
Use the following procedure to enable anonymous authentication for a Web site.
You must be a member of the Administrators group on the local computer to perform the following procedure or procedures. As a security best practice, log on to your computer by using an account that is not in the Administrators group, and then use the runas command to run IIS Manager as an administrator. At a command prompt, type runas /user:Administrative_AccountName "mmc %systemroot%\system32\inetsrv\iis.msc".
To enable Anonymous authentication
Configuration settings made at the Web Sites level are inherited by all of the Web sites on the server. You can override inheritance by configuring the individual site or site element.