When you use Internet Explorer to access the http://companyweb Web site from a server that is running Windows Small Business Server 2003 with Service Pack 2, you may be prompted to provide your credentials. After you provide your credentials and then click OK
third time, you receive the following error message:
401.1 - Unauthorized
This problem occurs only if you access the Web site from the
server. This problem does not occur if you access the Web site from a client
According to Microsoft Knowledge Base article 896861, users
receive this error message when the following conditions are true:
- They make local NTLM authentication requests to a Web site
that uses the NTLM authentication.
- The Web site is hosted on Internet Information Services
(IIS) 5.1 or IIS 6.
- The Web site has a name that is mapped to the local
The issue that is discussed in the "Symptoms" section triggers
these conditions for the following reasons:
- When you configure Windows Small Business Server 2003, the
SharePoint Web site is automatically configured to use only the NTLM
authentication. Therefore, Kerberos authentication is not enabled.
- A static DNS record is created in the DNS database. The
target host of the DNS record is the Fully Qualified Domain Name (FQDN) of the
- Windows Internet Explorer 8 introduces a security
improvement that expands the use of Service Principal Name (SPN) from the
Negotiate authentication to include the NTLM authentication. This security
improvement helps protect against credential reuse and helps protect the system
from loopback attacks.
This update automatically enables the Kerberos authentication on
the SharePoint Web site.
How to obtain this update
This update is available from the Microsoft Update Web site:
You must have .NET Framework 2.0 installed before you apply this
not have to restart the computer after you apply this update.
Update replacement information
This update does not replace a previously released
The English version of this update has the file
attributes (or later file attributes) that are listed in the following table.
The dates and times for these files are listed in Coordinated Universal Time
(UTC). When you view the file information, it is converted to local time. To
find the difference between UTC and local time, use the Time
tab in the Date and Time
item in Control
Collapse this tableExpand this table
|File name||File version||File
has confirmed that this is a problem in the Microsoft products that are listed
in the "Applies to" section.
For more information about
software update terminology, click the following article number to view the
article in the Microsoft Knowledge Base:
Description of the standard terminology that is used to describe Microsoft software updates