Best Enterprise Solution - By thorough Understanding of the Requirements, Proper Architecture, Implementation using Hi Tech. Optimized solution
http://weblogs.asp.net/scottgu/archive/2006/07/12/Recipe_3A00_-Enabling-Windows-Authentication-within-an-Intranet-ASP.NET-Web-application.aspx
http://msdn2.microsoft.com/en-us/library/ms998358.aspx
If you want to know more about Security and HowTo... about ASP.NET 2.0 Membership, Roles, Forms Authentication, and Security Resources ...
http://weblogs.asp.net/scottgu/archive/2006/02/24/438953.aspx