What Outlook Data Files Must be Opened from within Outlook Means?

Mark Regan
Published: June 10th, 2025 • 4 Min Read

If you have tried to open Outlook data files by double clicking on file Explorer and facing Outlook data files must be opened from within Outlook means error. Then you are not alone. This common issue arises because Outlook data files are designed to only be accessed on Outlook. In this article, we will explain common causes of this error, how to open your data files correctly, and how to troubleshoot issues related to Outlook data files that must be opened from within Outlook.

Correct Way to Open Outlook Data Files

First, Launch Microsoft Outlook and navigate to file.
Next, Click on open and export and select open Outlook data file.
Here, Select OST or PST file as you want to open.

Common Mistakes Users Make

Try to open OST or PST files by double clicking in Windows file explorer as it does not work. These files typically require Outlook to access it.
Dragging a data file into Outlook may seem intuitive but it’s not supported and often shows Outlook data files must be opened from within Outlook error.

Do New Outlook Versions Support PST/OST Files?

PST File: Currently, New Outlook does not allow importing OST/PST files. This feature is only available in Outlook classic.
OST File: These files are created automatically for Exchange or IMAP accounts. In New Outlook, users cannot manually manage or open OST files.

Method 1. How to Open Outlook Data Files Correctly(Outlook Classic)?

First, Open Microsoft Outlook and click on the file.
Then, Choose open and export and click on the open Outlook data file.
After that, Browse the OST/PST file as you wish to open.
Next, Click on OK to open Outlook data file.

Method 2. How to Open Outlook Data Files for Mac Users?

Open Outlook for Mac and navigate to Tools.
Click on Import and choose Outlook data file(OLM/OST file).
Select file and press Continue to import.
Now, you can access data in Outlook Mac.

How to Locate Default Outlook Data File Location?

If you want to locate Outlook data file location then follow procedure as we have stated for both Mac and Windows.

Solution 1. For Windows

First, Click on file and press on Account Settings.
Then, Hit on Account Settings and navigate to data files.
After that, Locate PST or OST files and click on open file location.

Default Path:

PST: C:\Users\[YourName]\Documents\Outlook Files\
OST: C:\Users\[YourName]\AppData\Local\Microsoft\Outlook\

Solution 2. For Mac

First, Open Finder.
Next, Navigate to: ~/Library/Group Containers/UBF8T346G9.Office/Outlook/Outlook 15 Profiles/.

Troubleshooting: Data File Won’t Open Even Within Outlook

Verify you have read/write access to the file and its not marked as Read-Only in file explorer.
Make sure the file isn’t in use on another program.
Microsoft offers an inbuilt ScanPST tool to repair Outlook data file.
Large Outlook data files may fail to load. Try to reduce file size or splitting archives if needed.
If the file works on another system or profile, the issues may be with your Outlook installation or user profile.

Help Questions

How do I Open OST file in Outlook?

You cannot open an OST file manually. It creates and manages automatically for Exchange, IMAP, or Microsoft 365 accounts. To access its data, just set up the account in Outlook, OST will load in the background.

Why is Outlook asking for Outlook Data File Password?

If the PST file is locked then Outlook asks for Outlook data file password when opening it. If you didn’t set one, it may be corrupted. Use PST Unlocker to unlock it or ScanPST Repair Tool to restore from backup if password is unknown.

How to fix Outlook Data Files usage is Disabled on this Computer?

This error often appears due to group policies or registry restrictions. Enable PST usage via Group policy editor or contact your IT admin to lift restrictions on Outlook data file usage.

Final Analysis

In this tutorial, we have shared all crucial information related to Outlook data files that must be opened from within Outlook users. You can follow approaches as we have stated below. If you have not installed Outlook then we recommend you to choose OST Viewer as it offers fully maintained results and no risk of losing any crucial information.