MSI File Extension: What is it and how to open it?

Windows Installer Package files are the most popular file type with MSI file extension, developed by Igor Pavlov for 7-Zip. Anonymous user data statistics suggest that MSI files are most popular in China and among those using Windows 10 devices. The vast majority of these users tend to use Google Chrome as their preferred internet browser.

What is an MSI file?

MSI file used to install and run Windows programs. A complete package for Microsoft Windows that contains installation information for a typical program, including essential files to install and installation location information. MSI files may also contain software update packages. MSI files are similar to EXE, but sometimes EXE may not include installer information and the program may run directly when the EXE file is run.

MSI file format

Windows Installer is actually an API (Application Programming Interface) and software component of Microsoft Windows used to install, remove and maintain software. Installation information and optional files are packaged as installation packages and loose relational databases organized into COM structured storages; Known as **MSI files**, they have the msi file extension. Packages with the file extension have **. mst ** contains ** Windows Installer conversion scripts ** and files with the extension **. msm ** contains ** merge modules ** and file extension **. pcp ** is used for ** debug creation properties **. Windows Installer becomes more advanced after making major changes from its previous versions, the installation API. A GUI framework and automatic generation of uninstallation sequences are new features of Windows Installer. It is now considered an alternative to standalone executable installer frameworks.

Logical structure of MSI packages

A package identifies the installation of one or more complete products and is typically identified by **GUID**.

The product consists of one or more components and is grouped into different functionalities. Windows Installer does not manage dependencies between different products simultaneously.

The logical structure of packages consists of the following elements:

**Products**: A single installed or running program or a group of several programs taken together is a product. The product is identified by a unique GUID.

**Features**: May contain a number of other components and sub-features. Smaller packages may consist of a single feature.

**Components**: A component is treated by Windows Installer as a unit; It may contain program files, folders, registry keys, COM components and shortcuts.

**Key Paths**: A key path is a specific file, ODBC data source, or registry key that the package author identifies as critical for a particular component.

How to open MSI files?

You need a suitable program like Windows Installer to open the MSI file. Without the proper software, you will receive a Windows message "How do you want to open this file?" or "Windows cannot open this file" or similar alarm on Mac/iPhone/Android. If you cannot open the MSI file correctly, try right-clicking or long-pressing on the file. Then click Open with and choose an app. You can also view the MSI file directly in the browser. Simply drag the file into this browser window and drop it.

Programs that open and convert MSI files:

Microsoft Windows Installer

Please refer to the previous paragraphs for more information about the main application. MSI files are often called Windows Installer executable files because this type of file is primarily created or used by this program.

Cerius2 (data) by BIOVIA

Cerius2 is an obsolete modeling and simulation software environment for UNIX-based systems. It uses some data saved in the MSI file. This file format is classified as Misc.

TruNEST (nesting data) by Magestic

TruNEST is interference management software used for CNC cutting and material optimization operations. Provides a simple solution for placing parts on sheet metal. Some of the embedded data used by this program is saved in an MSI file. This file format is classified as CAD.