Why is Outlook Not Opening in Windows 10?

Sometimes, MS Outlook users face the issue ‘Outlook not opening on a Windows 10 system’. When they try to open it, the application freezes and crashes, or doesn’t start at all. In this post, we have mentioned the reasons behind the issue and provided solutions to fix this problem.   

If you’ve installed MS Outlook on a Windows 10 system recently and the application isn’t opening, you should install the latest Outlook updates and try again. If this doesn’t fix the Outlook not working on Windows 10 issue, follow the solutions mentioned below. 

Why is Microsoft Outlook Not Opening in Windows 10?

Outlook users can face Outlook won’t open in Windows 10 issue due to many reasons. Below, we have explained these reasons, along with the solutions. 

Reason #1: Compatibility Issues 

Windows allows the users to run different applications in compatibility mode so that even old applications can work on newer or specific operating system. If you are running Outlook in compatibility mode, then turn off the setting and try to run Outlook again. 

Reason #2: Conflicting Add-ins 

There is a wide range of Outlook add-ins that you can use to enhance your Outlook experience. However, certain add-ins may prevent Outlook from running properly. You can disable such add-ins to resolve the issues.

Follow these steps:

  1. Press Windows + R keys to launch the Run utility.
  2. Enter outlook /safe in the input field and click OK. This will open Outlook in safe mode. All Outlook add-ins are automatically disabled in safe mode. 

If you are able to use Outlook in safe mode without any issues, then it confirms that the problem of Outlook won’t open in Windows 10 is caused by specific add-ins.

  1. Enable the Outlook add-ins one-by-one to identify the add-in that’s preventing Outlook from opening in Windows 10. 
  1. Remove the faulty add-in from the application.

Reason #3: Damaged MS Office Program  

Microsoft Outlook can become corrupt due to malware infection, abrupt shutdowns, etc. In these situations, repairing Microsoft Office program may also help fix the Outlook not opening in Windows 10 issue. 

To repair Office, follow these steps:

  1. Close all MS Office applications.
  2. Go to Windows Control Panel and click Programs and Features.
  3. In the list of installed applications, locate Microsoft Office
  4. Right-click Microsoft Office and then click Repair

Reason #4: Navigation Pane Issues

If there are any problems with the customizations in MS Outlook’s navigation pane, they can prevent the application from launching. You can reset the navigation pane by taking the following steps:

  1. Close Outlook.
  2. Press Windows + R keys to open the Run tool.
  3. Enter outlook.exe /resetnavpane in the text field and click OK

Reason #5: Large-sized Outlook App Data Folder

If the Outlook App data folder has become too large, it can create the Outlook not opening issue. In such a case, you can delete this folder to resolve the issue. To do that, follow these steps:

  1. Press Windows + R keys to open the Run tool.
  2. Enter %localappdata% in the input field and press Enter. Doing this will open the Local App Data folder. 
  3. Open the Microsoft folder and then find the Outlook folder. Delete the Outlook folder.
  4. Restart Outlook

Reason #6: Corrupt Outlook Data File 

You may face the issue of Outlook not working on Windows 10 if the Personal Storage Table (PST) file is corrupt. You can repair the Outlook PST file by using the ScanPST.exe tool, which is located in Outlook’s installation directory. This is a free tool that can fix minor corruption in PST file. If this tool fails to repair the PST, you can use an advanced third-party PST repair tool, such as Stellar Repair for Outlook. 


Sometimes, Outlook users face issues, such as Outlook not opening in Windows 10. Such issues may occur due to a missing update, faulty Outlook add-in, corruption in PST file, etc. You can follow the PST file recovery solutions given above to fix the issue.

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