The default authentication method for Microsoft IIS 5.0 is anonymous. The anonymous authentication is supported by Policy Agent 2.2. In addition to anonymous authentication, this web agent supports HTTP basic authentication. In this mode, the Windows system prompts the user for authentication by providing a dialog box. This prompt appears even though the user is still required to provide authentication credentials for Access Manager. This double authentication requirement can be turned off. For details on how to turn off the Windows system authentication, see Preventing an Additional Authentication Prompt: Preparing to Install Agent for Microsoft IIS 5.0.