Well lets look for the answere then.

This article describes how to configure Microsoft Internet Information Services (IIS) Web site authentication in Windows Server 2003. You can configure IIS to authenticate users before they are permitted access to a Web site, a folder in the site, or even a particular document contained in a folder in the site. Authentication in IIS can be used to strengthen the level of security on sites, folders, and documents that are not to be viewed by the general public.

Authentication in IIS is critical when resources are not meant for anonymous or public access, but when the Web server must be accessible to approved users over the Internet. Examples of Web site applications that require authentication access control include Microsoft Outlook Web Access (OWA) and the Microsoft Terminal Services Advanced Client.

back to the top

How to Configure Authentication in IIS
Start IIS Manager or open the IIS snap-in.
Expand Server_name, where Server_name is the name of the server, and then expand Web Sites.
In the console tree, right-click the Web site, virtual directory, or file for which you want to configure authentication, and then click Properties.
Click the Directory Security or File Security tab (as appropriate), and then under Anonymous and access control, click Edit.
Click to select the check box next to the authentication method or methods that you want to use, and then click OK.

The authentication methods that are set by default are Anonymous access and Integrated Windows authentication:
Anonymous access: When anonymous access is turned on, no authenticated user credentials are required to access the site. This option is best used when you want to grant public access to information that requires no security. When a user tries to connect to your Web site, IIS assigns the connection to the IUSER_ComputerName account, where ComputerName is the name of the server on which IIS is running. By default, the IUSER_ComputerName account is a member of the Guests group. This group has security restrictions, imposed by NTFS file system permissions, that designate the level of access and the type of content that is available to public users. To edit the Windows account used for anonymous access, click Browse in the Anonymous access box.

IMPORTANT: If you turn on anonymous access, IIS always tries to authenticate users by using anonymous authentication first, even if you turn on additional authentication methods.
Integrated Windows authentication: Formerly named NTLM or Windows NT Challenge/Response authentication, this method sends


Here is the link.
http://support.microsoft.com/default...uct=winsvr2003