Adding and Removing MIME Types

Multipurpose Internet Mail Exchange (MIME) types instruct a web browser
or mail application how to handle files received from a server. For
example, when a web browser requests an item on a server, it also
requests the MIME type of the object. Some MIME types, like graphics,
can be displayed inside the browser. Others, such as word processing
documents, require an external application to be displayed.

When a web server delivers a web page to a client web browser, it also
sends the MIME type of the data it is sending. If there is an attached
or embedded file in a specific format, IIS also tells the client
application the MIME type of the embedded or attached file. The client
application then knows how to process or display the data being received
from IIS.

IIS can only operate files of registered MIME types. These types could
be defined both on the global IIS level and on the website or virtual
directory level. Globally-defined MIME types are inherited by all
websites and virtual directories while ones defined on the website main
or virtual directory level are used only for the area where they are
defined. Otherwise, if the web server receives request for a file with
unregistered MIME type, it returns the 404.3 (Not Found) error.

To add a MIME type for a virtual directory within a website:

1. Go to Websites & Domains and find the website’s domain name.
2. Click Virtual Directories.
3. Navigate to the required virtual directory and click the
   corresponding link with its name.
4. Click the MIME Types tab.
5. Click Add MIME Type.
6. Specify the following:
   • Type the file name extension in the Extension field. File name
     extension should begin with a dot (.), or a wildcard (*) to serve
     all files regardless of file name extension.
   • Specify the file content type in the Content field.
   • You can either select the appropriate value from the list or
     define a new content type. To do this, select Custom and enter
     the content type in the input box provided.
7. Click OK to finish the creation.

To edit a MIME type for a virtual directory within a website:

1. Go to Websites & Domains and find the website’s domain name.
2. Click Virtual Directories.
3. Navigate to the required virtual directory and click the
   corresponding link with its name.
4. Select the MIME Types tab.
5. Select the required MIME type in the list.
   • Type the file name extension in the Extension field. File name
     extension should begin with a dot (.), or a wildcard (*) to serve
     all files…