How to Solve Outlook Won't Open Issue in Windows and Mac?

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Are you someone who uses Outlook every single day? Chances are you might face a problem, where the Outlook won’t load, freezes, or is unresponsive (aka stuck). Explained in this article are the ways to fix Outlook not opening on Windows 11, 10, 8, or 7. However, if you are sure that the issue is because of Outlook data file corruption, then make use of Remo Repair Outlook PST to easily repair severely corrupt PST files in Outlook with a few simple clicks.

Outlook application is a go-to tool for all of our day-to-day work needs. Right from making appointments to sending emails, and taking notes to monitoring tasks. however, you might at some point or the other notice that Microsoft Outlook won’t open.  If you are one of those who have faced this issue. Then you have ended up in the right place. Mentioned here are various reasons as well as ways to fix this issue.

Why is My Outlook Not Opening?

There are numerous reasons why your Outlook won’t start. Here are a few of those reasons.

  • Using faulty add-ins or extensions.
  • Corrupt Outlook Profile.
  • Virus or other Malware Attack.
  • Using an Outdated Version of Outlook.
  • Using an Outdated Version of Windows.

How to Fix Outlook Not Opening in Windows? 

Discussed here are several ways that are guaranteed to fix the problem of Outlook not opening on a computer.

  1. Disable Outlook Add-ins or toolbar extensions.
  2. Make sure that the outlook is not in compatibility mode.
  3. Try a different version of Outlook.
  4. Reset the Navigation pane.
  5. Scan the system for Viruses.
  6. Repair Corrupt Outlook Data.

Open Outlook in Safe Mode

First of all, we suggest you start Outlook in Safe Mode and try the methods mentioned below. Here is how you can open Outlook in safe mode.

Step 1:  Press Windows + R key, type in Outlook /safe, and click on the OK button.

Step 2: Choose the Outlook Profile and click on OK.

Step 3: If asked for login credentials, enter your password and click on Accept.

Safe Mode is a feature that lets the user launch and run Microsoft Outlook with a restricted number of options and features also blocking extensions and add-ins. To help you troubleshoot minor issues or some bigger problems in Outlook.

Important Note: If you want to discover how to make boring activities in Outlook more enjoyable, take note. We suggest reading this post to learn how to use Quick Parts in Outlook to streamline routine activities.

Method 1: Disable Outlook Add-ins or toolbar extensions.

Using too many Outlook add-ins or extensions might also be the reason why the Outlook app won’t open on your Windows system. This can be due to unexpected or continuous conflict between two or more add-ins. We highly recommend our users try disabling the add-ins one by one and see which one was at fault.

Step 1: Launch the Outlook application.

Step 2: Find and click on File from the top of the screen. Followed by Options and then Add-ins.

Step 3: A new window will appear on your screen, consisting of all the installed add-ins.

list of all add-ins appear

Step 4: Select Manage: COM Add-ins and click on the Go button.

Step 5: Uncheck the add-ins that you have decided to disable and click on OK.

select the add-ins you want to disable

Step 6: Close Outlook and try to restart the application. 

Method 2: Check if Outlook is in Compatibility Mode.

The Compatibility Mode is an inbuilt feature that is designed to run an older version of Microsoft Outlook on a newer version of Windows such as Windows 11 or 10. At times you might have accidentally enabled compatibility mode due to which the Outlook app is not opening in Windows 10 or other versions.
We suggest you check and disable the compatibility mode. 

Step 1: Right-click on Outlook’s desktop icon and click on properties.
Step 2: Outlook’s properties window will appear on your screen. Click on the compatibility mode.
Step 3: Untick the Run this program in compatibility mode for option.
Step 4: Click on Apply and hit the Ok button.

Method 3: Update to the Newer version of Outlook:

If the issue still persists, you can try a newer version of Outlook which is available. Upgrading to a newer version of Outlook might not just solve Outlook won’t load issue but also other problems such as the set of folders cannot be opened in Outlook.  

Follow the steps to install a newer version of the Outlook app on your computer system.

Step 1: Click on the File option from the top of the screen.

Step 2: Select the Office Account option from the drop-down menu.

Step 3: Click on Update Options.

Step 4: Click on the Update Now option to update the Outlook email client.

Method 4: Reset the Navigation Pane

There might be an issue with the navigation pane which is preventing Outlook to open and work properly. It makes sense to try resetting the navigation pane, whereby you get rid of all the customizations and optimizations made to the navigation pane in Outlook.

Step 1: Hit Windows Key + R key simultaneously.

Step 2: Type in the following command “Outlook.exe /resetnavpane” and click on OK.

Step 3: Launch Outlook. The navigation pane should be reset by now.

In some cases, this method works. If this method didn’t work out well for you. Then kindly try the next method.

Method 5: Scan the system for Viruses.

A virus attack might be a possible reason why you are unable to open the Outlook application. That’s why we always suggest our users regularly run anti-virus scans on their systems to prevent any unexpected virus attack.  If in case you are not at all using any antivirus software. We highly suggest installing and using any reliable software. You can also use Windows Defender Firewall.

At times you might be able to open and run the Outlook application without any issues, but there might be certain issues like sent items not showing in the sent folder of Outlook or sudden disappearance of the draft emails from the drafts folder, or Outlook email not opening. All of these are signs of Outlook's profile getting corrupt.

If all of the above methods have failed to fix the “Cannot Open Outlook in Windows” problem. Follow the next method that is guaranteed to repair corrupt Outlook data files.

Method 6: Repair Outlook Data Files

There are two ways to repair Outlook data files, one is by making use of scanPST. This is a free DIY solution, which also has its own share of limitations and directly works on the original file, thereby putting your PST file at risk.

Hence we recommend a far better and safer way to repair your Outlook data file using a professional Outlook PST repair tool by Remo.

Remo Repair Outlook PST is an exclusive tool that is built for repairing corrupt Outlook data.  The tool can repair severely corrupted or damaged Outlook files with just 3 simple clicks on any version of Outlook. 

Free Download For Windows

Step 1: Open the tool, from the main screen, and choose any one of the options depending on your needs.

  1. Open Default PST File: Finds the default location of your PST file.
  2. Select PST File Manually: Try this method if in case you know the location of the PST files that need to be repaired.
  3. Find All Your PST Files: This option deploys the algorithms to scan the entire drive and provide a list of all available PST Files. Use this option if you don’t know the location of corrupt PST files.
Select option to find the pst file

Step 2: Choose between the two scan options.
1. Normal Scan: Select this option if the level of corruption or damage is relatively low.
2. Smart Scan: You can choose this option in either of the two situations. Firstly, when you want to repair and recover various data items such as emails, contacts, and notes from a severely corrupt or damaged PST file. Second, when the normal scan has failed.

Repair severely corrupt or damaged PST file

Step 3: Click on the Repair button to start the Outlook file repair. Once the scan is done, you can preview the repaired PST files.

Step 4: If you are happy with the result. Kindly activate the tool and save the repaired Outlook files.

What to do when Outlook Won’t Open on Mac?

If you are wondering why you cannot start Microsoft Outlook on a Mac system or if the application becomes unresponsive or freezes unexpectedly. Then keep reading this section to find out an answer to fix the problem.

If you are using 14 versions of Microsoft Office or anything lower than that, the application will not run in Catalina or Big Sur. Office 2016 for Mac is no longer supported by Microsoft (no bug fixes or OS compatibility updates after October 2020). Office 2016 might or might not work on Big Sur.

So the easiest way to fix the problem is by updating Outlook.

How to Update to the Newest Version of Microsoft Outlook?

Step 1: Launch the Outlook App.
Step 2: Click on Help.
Step 3: Select Check for Updates.
Step 4: Choose Update and download the updates if available.


Here we end our discussion on how to repair Outlook not opening in Windows and Mac. if you have any additional questions, feel free to drop them in the comment section below.

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Tony Landry

Tony Landry is a Web Content Editor at Remo Software. He loves to write, edit, and manage content for users trying to troubleshoot and fix problems on Windows, Outlook, storage drives and Cloud storage networks.

He has published more than 200 articles in Remo Software blog. He actively engages in research and problem-solving techniques to consistently generate great web content. Fixing various hardware problems on computer and storage devices along with a great knack for fixing Outlook errors, Tony is also the fun-time IT guy for all his work friends. He lives in the San Francisco Bay Area and enjoys cycling.

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