To install an MSIX file on Windows 10, double-click the .msix or .msixbundle file. Windows opens App Installer, which shows the app name, publisher, and permissions. Click Install, and the app appears in your Start menu when it’s done. If double-clicking doesn’t work, install the App Installer app from the Microsoft Store, or run Add-AppxPackage -Path "C:\path\app.msix" in PowerShell.
Only install MSIX packages from publishers you trust. Here’s how to install them, what the common errors mean, and how to uninstall them.
Method 1: Install with App Installer
- Download the .msix or .msixbundle file from the developer’s official website.
- Double-click the file.
- Check the Publisher name and the capabilities the app asks for.
- Click Install. Leave Launch when ready checked to open it right away.
If nothing happens when you double-click
App Installer may be missing or out of date. Open the Microsoft Store, search for App Installer, and click Get or Update.
Method 2: Install with PowerShell
- Right-click the Start button and choose Windows PowerShell.
- Run:
Add-AppxPackage -Path "C:\Users\YourName\Downloads\app.msix", replacing the path with your file’s location. - Press Enter and wait for it to finish.
To copy a file’s path, hold Shift, right-click the file, and choose Copy as path.
Allow sideloading on older Windows 10 versions
Current Windows 10 versions allow installing apps from outside the Store by default. On older versions, go to Settings > Update & Security > For developers and choose Sideload apps. On work PCs, your organization may block this.
Common MSIX install errors
| Error | What it means and what to do |
|---|---|
| “Ask the developer for a new app package… not signed with a trusted certificate” (0x800B0109) | The package’s certificate isn’t trusted on your PC. Get the app from the official source. Developers testing their own apps can install the certificate to Trusted People. |
| “This app package is not supported for installation by App Installer because it uses certain restricted capabilities” | Use the PowerShell method instead. |
| 0x80073CF3 or dependency errors | A required framework is missing. Install the dependency packages the developer provides, then retry. |
| 0x80073D02 | The app is running. Close it and try again. |
| Your Windows version isn’t supported | The app needs a newer Windows build. Update Windows or use an older app version. |
How to uninstall an MSIX app
- Right-click the app in the Start menu and choose Uninstall.
- Or go to Settings > Apps > Apps & features, click the app, and choose Uninstall.
Frequently asked questions
What is an MSIX file?
MSIX is Microsoft’s modern app package format. It installs cleanly, updates easily, and uninstalls without leaving files behind.
Is it safe to install MSIX files?
MSIX packages must be digitally signed, which shows who published them. Still, only install packages from developers you trust.
What’s the difference between MSIX and MSI?
MSI is the older Windows Installer format. MSIX runs apps in a more contained way and supports automatic updates.
Can I install MSIX on Windows 11?
Yes. The steps are the same.
Kermit Matthews is a freelance writer based in Philadelphia, Pennsylvania with more than a decade of experience writing technology guides. He has a Bachelor’s and Master’s degree in Computer Science and has spent much of his professional career in IT management.
He specializes in writing content about iPhones, Android devices, Microsoft Office, and many other popular applications and devices.