Ages ago, I wrote a little DHTML tool to help people determine the appropriate authentication settings to use with different browsers, servers and Web servers. It helped a good many people, but it was simple. Today, the IIS team has released a much more complete tool to help diagnose authentication and authorization issues.

These links should be live "any moment" now!!

x86:  http://www.microsoft.com/downloads/details.aspx?FamilyId=E90FE777-4A21-4066-BD22-B931F7572E9A&displaylang=en
IA-64: http://www.microsoft.com/downloads/details.aspx?FamilyId=603092CA-37FB-4E67-83B5-21B9CDD5537D&displaylang=en
AMD64: http://www.microsoft.com/downloads/details.aspx?FamilyId=63AAF167-2138-4231-B6ED-56298044BD3B&displaylang=en