IIS hidden static files return HTTP 404 or Access Denied errors

This article helps you resolve the error (HTTP 404 or Access Denied) that occurs from the IIS hidden static file.

Original product version:   Internet Information Services
Original KB number:   216803


We strongly recommend that all users upgrade to Microsoft Internet Information Services (IIS) version 7.0 running on Windows Server 2008. IIS 7.0 significantly increases Web infrastructure security. For more information about IIS 7.0, see Home: The Official Microsoft IIS Site.


Static files that have the hidden attribute set may return an HTTP 404 or an Access Denied error when browsed, while dynamic files can still be browsed.


This behavior is by design.


Configuring access control for all Web files should always be implemented through NT File System (NTFS) permissions.

More information

Dynamic files such as Active Server Pages (ASP) or Server-Side Includes (SSI) are implemented through script-mapped Internet Server Application Programming Interface (ISAPI) extensions, in this case the Asp.dll and Ssiinc.dll files respectively. These extensions preprocess the executable code in the files being requested and can therefore read hidden files and return the expected HTML output to a client. Direct Web browsing of hidden static files results in a File not Found or an Access Denied error message.