Fix MSG File Association on Windows 11

The Problem: "How do you want to open this file?"

If you've recently upgraded to Windows 11 or received an Outlook `.msg` file for the first time, you might have encountered a frustrating issue: double-clicking the file doesn't open it. Instead, Windows prompts you with a dialog asking "How do you want to open this file?"

This happens because Windows doesn't include a default program to open MSG files out of the box. Unless Microsoft Outlook is installed on your computer, Windows simply doesn't know what to do with the file format.

Why File Associations Break

Even if you previously had a program that could open MSG files, associations can break due to:

• A major Windows update resetting default apps.
• Uninstalling an older version of Microsoft Office.
• Another program incorrectly taking over the `.msg` extension.

Fortunately, fixing the association so MSG files open automatically is a quick process.

Step 1: Get a reliable MSG Viewer

If you don't have Microsoft Outlook (and don't want to pay for a subscription just to read a file), you'll need a dedicated viewer.

We recommend OpenMSG, a fast, private, and capable MSG viewer for Windows 11. It's completely standalone, processes files locally, and handles attachments flawlessly.

1. Open the Microsoft Store.
2. Install OpenMSG.
3. Wait for the installation to complete (it only takes a few seconds).

Step 2: Set the Default App in Windows 11

Once you have a compatible app, you need to tell Windows to always use it for `.msg` files.

The Right-Click Method (Fastest)

1. Find any `.msg` file on your computer.
2. Right-click on the file and hover over Open with.
3. Click on Choose another app.
4. In the window that appears, look for OpenMSG in the list.
5. Crucial step: Check the box at the bottom that says Always use this app to open .msg files.
6. Click OK.

The Windows Settings Method

If the right-click method doesn't work, you can force the change through Windows Settings:

1. Press `Win + I` to open Settings.
2. Go to Apps from the left-hand menu.
3. Click on Default apps.
4. Scroll all the way down and select Choose defaults by file type.
5. In the search box, type `.msg`.
6. Click on the current default program (or the "+" icon if none is set) and choose OpenMSG.

Verifying the Fix

With the association set, the icon for your `.msg` files should change to the OpenMSG icon. Double-click any MSG file, and it should immediately open and display the email contents properly.

By taking 60 seconds to configure this, you'll ensure a seamless experience the next time you need to review an exported email.