What is the Use of Files with the .msi File Extension?

What is the .msi file extension?

MSI is an acronym for MicroSoft Installer and is one of the core components of the installer package used for Microsoft Windows. All the software designed for the Windows operating system is packaged with Windows installer and it includes the msi package with the .msi file extension.

What is the .msi file extension used for?

Windows Installer was earlier known as the Microsoft Installer. It is an engine for deploying, maintaining and completely removing software packages from Windows systems. Microsoft Installer was used previously to design packages for Windows and had the .msi file extension until it was modified with a better version of installer called ?Windows Installer?.

Windows installer has two components that work in conjunction with each other.? They are:

  1. Installer Service ? It is a client-side installer service and is governed by the file msiexec.exe. When this file is called by setup.exe, it transfers the control to msi.dll that reads the package with the .msi file extension. The msiexec.exe file makes all the necessary changes in the system like updating registry keys, copying files to the hard disk, and creating shortcuts etc.
  2. Package ? This is the file that has all contents related to the software and has the .msi file extension. The package with the .msi file extension contains detailed information about the installation during the execution of the file. This package is like a database that carries all instructions to install or remove the file in different environments.

Windows installer changes the ?registered file type? of the .msi file extension to open with it. When the .msi file is double clicked, it uses the msiexec.exe, which is the installer file of Windows installer, to run it.

Once Microsoft released the Windows installer package, they made it a rule to include them in all the applications designed for Windows OS.

What are the different kinds of software used to open the .msi file extension?

The .msi file extension format can be opened using:

  1. Windows Installer
  2. File compression software like WinZip and Winrar
  3. Third-party installers like NSIS (Nullsoft Scriptable Install System)
  4. Third-party file helper tools that are designed to open files with different file extensions, including the .msi file extension. These tools also help in repairing file errors that may be preventing you from working with a particular file type on your system.