Improper NTFS Permissions May Result in IIS Failure

 Last reviewed: April 18, 1997
Article ID: Q155253

The information in this article applies to:
  • Microsoft Internet Information Server versions 1.0, 2.0, and 3.0

SUMMARY

Improper modification of Microsoft Windows NT file system (NTFS) permissions may create an environment where browser clients fail when attempting to access the Microsoft Internet Information Server (IIS) publication services.

MORE INFORMATION

Microsoft Windows NT version 4.0 installs on a new NTFS partition with change permission for the group Everyone. Improper NTFS access permissions involving other Windows NT accounts such as System, Network, Interactive, and IUSR_ComputerName may affect the operation of IIS. Most of these improperly defined permissions result in a browser client receiving an HTTP response of 401 Access Denied.

As an example, consider an IIS server that has been configured with only Allow Anonymous access in the in WWW Services tab of the Internet Service Manager. The web master has set the following permissions on his or her NTFS WWW publication directory wwwroot of: 

   CREATOR OWNER                 Full Control
   ComputerName\Administrators   Full Control
   IUSR_ComputerName             Full Control
   Everyone                      No Access
   System                        Full Control
The web master calls Microsoft Product Support, describing an issue in which no one can access his or her IIS server from a WWW client browser. A sniffer trace shows that all of the client browsers receive a 401 Access Denied error message in the HTTP response.

The problem is the NTFS permissions. The Web master has allowed the IIS anonymous user account IUSR_ComputerName full access, but the web master has also explicitly denied the group Everyone. The IUSR_ComputerName account belongs to the group Everyone. An explicit deny always takes precedence over an allow, therefore no browser client can access the IIS server.

Before contacting Microsoft Product Support Services, customers are encouraged to check the NTFS permissions to verify that any modified access permission is not the cause of improper IIS functionality.

For more information on issues related to NTFS permission, please see the following articles in the Microsoft Knowledge Base: 

   ARTICLE-ID: Q109076
   TITLE     : Removing Permissions to an NTFS Partition May Prevent
               Startup

   ARTICLE-ID: Q130016
   TITLE     : Removing Everyone On Root Dir. Leaves Limited Virtual Memory

   ARTICLE-ID: Q137155
   TITLE     : Users Without System32 Permissions Cannot Log On

   ARTICLE-ID: Q137400
   TITLE     : Changing Default Permissions Causes STOP 0xC000021A

   ARTICLE-ID: Q138923
   TITLE     : Partitions Displaying as Unknown in Disk Administrator

Additional query words: prodiis
Keywords : iisconfig iissetup kbnetwork
Version : 1.0 2.0 3.0
Platform : NT WINDOWS
Issue type : kbhowto

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Last reviewed: April 18, 1997
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