http://msmvps.com/blogs/abu/archive/2008/03/01/windows-authentication-asp-net-and-iis.aspxThese links help you to understand and implement Windows Authentication in ASP.NET Application using Microsoft Internet Information Services (IIS) ... http://msdn2.microsoft.com/en-us/library/ms998372.aspx http://www.microsoft.com/technet/prodtechnolenCommunityServer 2008.5 SP2 (Build: 40407.4157)