.MSI file extension

To open .MSI files on Windows, double-click the .MSI file to launch the Windows Installer wizard, then follow the prompts.

To open a .MSI file, use Windows Installer on Windows (double-click it or run it with msiexec). On macOS, Linux, iOS, and Android, .MSI files are not generally usable as installers—transfer the file to a Windows PC if you need to install the software.

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Last updated: June 10, 2026 · Reviewed by Julian Stricker

What “reviewed” means on this page

Format fit: whether the “what is this file?” description matches common real-world use of the extension, including category, typical MIME types, and aliases.
Opening paths: whether Windows / macOS / Linux steps read plausibly for current OS dialogs and default apps; we remove fantasy menus and unsafe shortcuts.
Security framing: whether risk notes match the extension class (for example executables vs plain data) and whether affiliate wording does not contradict the security section.
Sources and further reading: whether external links point to vendors, standards bodies, or other primary references where possible; we avoid inventing details we cannot ground.
Limits: this is clarity and safety-messaging QA, not a guarantee that every statement is exhaustive or that every binary you download is harmless.

Full methodology in the Imprint — The Imprint also states where AI is used and what that does—and does not—replace.

Open on your device

Choose your operating system for a dedicated step-by-step opening guide.

How to open .MSI files

Use these platform-specific instructions to open .MSI files safely.

Windows

Double-click the .MSI file to launch the Windows Installer wizard, then follow the prompts.
If you need command-line control (install/repair/uninstall), open Command Prompt and use msiexec with the .msi file (for example, to run an install from the command line).
If Windows blocks or warns about the file, verify the source before proceeding (only run installers you trust).

Full Windows guide

Mac

.MSI files are Windows installer packages and are not typically installable on macOS. If your goal is to install the software, obtain a macOS-native installer from the software vendor.
If you received an .MSI intended for Windows, transfer it to a Windows PC to run it with Windows Installer.

Full Mac guide

Linux

.MSI files are Windows installer packages and are not typically usable as native Linux installers. If you need the software on Linux, look for a Linux package from the vendor instead.
If the .MSI is meant for Windows deployment, transfer it to a Windows system and run it with Windows Installer/msiexec.

Full Linux guide

iOS

.MSI files are not usable as installers on iOS. If you need to use the software, you’ll typically need a Windows PC to run the .MSI.

Full iOS guide

Android

.MSI files are not usable as installers on Android. If you need to install what it contains, transfer the file to Windows and run it with Windows Installer.

Full Android guide

Security notes

.MSI files are executable installation packages: running one can install software, change system settings, and potentially add persistence. Treat them like any other program installer and only run packages from trusted publishers.
Be cautious with unexpected .MSI files received via email or chat; attackers may use MSI installers as a delivery mechanism for malware because they can run installation actions through Windows Installer.
Prefer obtaining MSI packages directly from the software vendor or your organization’s managed software distribution, and avoid running modified or repackaged installers from unverified sources.

Security software for programs and installers

The operating system may run these files, launch an installer, or (for app packages such as APK or IPA) install runnable application code on a device. Treat unexpected downloads with extra care. Up-to-date antivirus helps detect known malware, including files disguised with double extensions or misleading names.

Avast

Avast offers free and premium antivirus software that protects against viruses, malware, ransomware, and phishing. Scan files before opening them to ensure safety.

Norton

Norton 360 delivers comprehensive antivirus protection, VPN, and identity theft monitoring. Scan files for threats before opening to keep your device secure.

We may earn a commission when you use affiliate links. This supports our free file extension guides.

Can't open this file?

These are the most common causes and fixes when .MSI files fail to open.

Common reasons

The .MSI won’t run or opens with the wrong app
Windows Installer reports an error or install fails
The file looks like an “archive,” but you can’t browse its contents

Fix steps

On Windows, try double-clicking again; if it still fails, use the Windows Installer command tool (msiexec) to run the package.
If you are on macOS/Linux/iOS/Android, move the .MSI to a Windows PC—.MSI is primarily for Windows Installer.

OS-specific troubleshooting

What is a .MSI file?

.MSI is the Windows Installer Database format for installation packages. It contains installation logic and resources used by Windows Installer to install applications, apply changes, or uninstall them. Windows uses Windows Installer (and msiexec.exe) to process these packages.

Background

MSI packages are a core part of the Windows Installer technology used for software deployment on Windows. Instead of being a simple “archive,” an .MSI file is an installation database that describes what to place on disk, what registry changes to make, and how the application should be configured during install, repair, or uninstall.

Common MIME types: application/x-msi

Common .MSI issues

The .MSI won’t run or opens with the wrong app

Windows may not be associating .MSI with Windows Installer correctly, or you may be trying to open it on a non-Windows platform.

On Windows, try double-clicking again; if it still fails, use the Windows Installer command tool (msiexec) to run the package.
If you are on macOS/Linux/iOS/Android, move the .MSI to a Windows PC—.MSI is primarily for Windows Installer.

Windows Installer reports an error or install fails

The package may be incompatible with your system, require elevated privileges, or be incomplete/corrupted.

Re-download the .MSI from the original publisher to rule out a partial or corrupted download.
Run the installer with appropriate permissions (many installs require administrative rights).
If you manage deployments, use msiexec to get clearer installation behavior and diagnostics (for example, to control install/repair/uninstall actions).

The file looks like an “archive,” but you can’t browse its contents

.MSI is an installer database format, not a general-purpose archive you open like a .zip.

If your goal is to install software, run it with Windows Installer (double-click or msiexec).
If your goal is to inspect package behavior, use Windows Installer tooling and documentation (rather than renaming the extension).

FAQ

Is an .MSI just a compressed archive?

No. An .MSI is a Windows Installer database/package designed to be processed by Windows Installer. While it contains embedded resources, it is primarily an installation package rather than a general-purpose archive format.

How do I install an .MSI from the command line?

Use Microsoft’s Windows Installer command-line tool, msiexec.exe, which can install, modify, or uninstall MSI packages. See Microsoft Learn for supported options and examples.

Can I open or run .MSI files on macOS, Linux, iOS, or Android?

Generally no. .MSI is a Windows Installer format. If you need the software on those platforms, you usually need a platform-native installer from the vendor; otherwise, run the .MSI on Windows.

Is the MIME type application/x-msi official?

It is commonly used in practice, but the authoritative registry for standardized media types is IANA; consult IANA’s media types registry to verify whether a type is officially registered.

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