What is MIME type "application/x-ms-installer"?

A MIME type is a string that tells browsers and other tools how to handle a particular kind of file.

The application/x-ms-installer MIME type represents files used by the Microsoft Windows Installer system. It handles software setup, modification, and patching processes on Windows systems.

This MIME type is tied to installation packages, transforms, and patches. For example, setup packages are stored in files like MSI.

Installation: Packages install software automatically.
Transformation: Transforms customize installations using files such as MST.
Patching: Patches apply updates or fixes through files like MSP.

The system uses this MIME type to improve compatibility and security during software deployment. It also supports silent installations and managed updates. For more detailed technical insights, refer to the Microsoft Windows Installer documentation.

Associated file extensions

.msi, .mst, .msp

Usage Examples

HTTP Header

When serving content with this MIME type, set the Content-Type header:


    Content-Type: application/x-ms-installer

HTML

In HTML, you can specify the MIME type in various elements:


    <a href="file.dat" type="application/x-ms-installer">Download file</a>

Server-side (Node.js)

Setting the Content-Type header in Node.js:


    const http = require('http');
    
    http.createServer((req, res) => {
      res.setHeader('Content-Type', 'application/x-ms-installer');
      res.end('Content here');
    }).listen(3000);

Associated file extensions

.msi, .mst, .msp

FAQ

What is a MIME type?

A MIME (Multipurpose Internet Mail Extensions) type is a standard that indicates the nature and format of a document, file, or assortment of bytes. MIME types are defined and standardized in IETF's RFC 6838.

MIME types are important because they help browsers and servers understand how to process a file. When a browser receives a file from a server, it uses the MIME type to determine how to display or handle the content, whether it's an image to display, a PDF to open in a viewer, or a video to play.

MIME types consist of a type and a subtype, separated by a slash (e.g., text/html, image/jpeg, application/pdf). Some MIME types also include optional parameters.

How do I find the MIME type for a file?

You can check the file extension or use a file identification tool such as file --mime-type on the command line. Many programming languages also provide libraries to detect MIME types.

Why are multiple MIME types listed for one extension?

Different applications and historical conventions may use alternative MIME identifiers for the same kind of file. Showing them all helps ensure compatibility across systems.