CAUSE - This issue occurs if the Authenticated Users group does not have access permissions to the Exchsrvr\exchweb folder.
RESOLUTION - Here at source link: http://support.microsoft.c
Main Topics
Browse All TopicsHi, when going here:
http://www.mbs.ac.uk/corpo
We get this error:
You are not authorized to view this page
HTTP 401.3 - Access denied by ACL on resource
We get this error on all our client machines that route through our Microsoft Proxy Server 2.0
If we connect a machine directly to the Internet via dialup, we get prompted with a normal NT style (NTLM?) login box, which then works fine.
We cannot however, seem to get prompted to logon when routing through MSP2.0, just an instant 401.3 error.
Quite urgent, maximum points.
This Question has been solved and asker verified All Experts Exchange premium technology solutions are available to subscription members.
Experts Exchange has been collecting answers to technology questions since 1996…3 million and counting! If you have a question, chances are we already have your answer.
If you can't find the exact answer you're looking for, ask our exclusive community of 50,000 experts. You’ll get a personalized answer from a trusted professional.
Thousands of free tech tips, tricks, how-to’s and tutorials are available in our peer reviewed articles section. See for yourself how smart our experts are, no login required.
Access the answers to your technology questions today.
30-day free trial. Register in 60 seconds.
Members of the expert community talk about why the experience at Experts Exchange is different than what you will find anywhere else.

Try it out and discover for yourself.
30-day free trial. Register in 60 seconds.
Join the community of experts here and help other tech pros by answering question in your area of expertise. You can earn FREE access to all Experts Exchange's premium features and resources.
CAUSE - This issue occurs if the Authenticated Users group does not have access permissions to the Exchsrvr\exchweb folder.
RESOLUTION - Here at source link: http://support.microsoft.c
SYMPTOMS
When you view a SQL Server 2000 Service Pack 2 database in your browser using HTTP on Windows Server 2003, you may receive the following error message:
Error 401.3 Access Denied
You are not authorized to view this page.
CAUSE
This behavior occurs because the SQLXML ISAPI extension DLL is not enabled in Internet Information Services (IIS) Server on Windows Server 2003. You must enable this DLL to use HTTP to view a SQL Server 2000 SP2 database in your browser in Windows Server 2003.
RESOLUTION
To resolve this problem, enable the SQLXML ISAPI extension DLL in IIS Server on Windows Server 2003, and set the WWW service to IIS 5.0 isolation mode instead of IIS 6.0 mode. To do this, follow these steps:
http://support.microsoft.c
With many more possibilities here:
http://support.microsoft.c
Back to work, hope this helps you.
Asta
Business Accounts
Answer for Membership
by: astaecPosted on 2004-04-14 at 07:32:40ID: 10823743
Authentication May Fail with "401.3" Error If Web Site's "Host Header" Differs from Server's NetBIOS Name om/default .aspx?kbid =294382
http://support.microsoft.c
Many more, but this will get you started.