Reference

MSI (Windows installer)

An MSI file is a Windows Installer package — a database of files, registry entries, and instructions that the Windows Installer service uses to install, repair, or remove a program cleanly.

Files & formatsWindows

MSI (Windows installer)

Also known as: MSI file, .msi installer, Windows Installer package

An MSI file is a Windows Installer package — a database of files, registry entries, and instructions that the Windows Installer service uses to install, repair, or remove a program cleanly.

Windows Installer package (files + registry + rules)
Supports clean repair and uninstall
Common for enterprise software deployment

A structured installer

Unlike a plain setup.exe, an MSI is a structured package read by the built-in Windows Installer engine. It records exactly what gets installed — files, shortcuts, registry keys — so Windows can repair or uninstall the program reliably later.

This structure also makes MSIs convenient for IT to deploy across many machines.

Installing and managing MSI files

Double-click an MSI to launch the installer, or run it silently from the command line for automated deployment. Installed MSI apps appear in Settings > Apps for removal.

As with any installer, only run MSIs from sources you trust, since they make system changes.

Related terms

Keep reading the reference.

Files & formatsArchive fileAn archive file bundles many files and folders into one container — for example a ZIP, RAR, or 7z. Most archives also compress their contents to save space, but some (like plain TAR) only bundle without shrinking anything.General Files & formatsDisk imageA disk image is a single file that mirrors the entire contents of a disk or volume — its file system, structure, and data. Common types include ISO (discs), DMG (macOS), and IMG. You mount or write a disk image rather than just extracting files from it.General Storage conceptsCompression (lossy vs lossless)Compression shrinks a file by encoding its data more efficiently. Lossless compression rebuilds the original exactly, while lossy compression permanently discards detail the eye or ear is least likely to notice in exchange for much smaller files.General