How to fix 'Cannot Start Microsoft Outlook' error on Windows

This guide will provide effective tips for backing up and running Outlook on Windows PC.

1. Run Outlook in Safe Mode

Third-party add-ins can sometimes interfere with the Outlook application and prevent it from opening on your PC. To test this possibility, you can open Outlook in Safe Mode. This will allow the app to run without any add-ins or custom settings, helping you determine if the problem is caused by an add-in or something else.

To open Outlook in Safe Mode:

1. Press Win + R to .
2. Type Outlook.exe /safe in the text field and press Enter .

If Outlook opens and works as expected in Safe Mode, it's possible that one of your add-ins is causing the "Cannot start Microsoft Outlook" error. To determine the cause of the problem, you need to disable all your add-ins and then enable them one by one. Here's how:

1. In the Outlook app, go to File > Options .
2. Select the Add-ins tab in the Outlook Options window .
3. Click the Go button next to COM Add-ins .
4. Uncheck all checkboxes to disable all add-ins, then click OK .

Restart the Outlook application, then enable each add-in until the problem occurs again. Once you identify the problematic add-in, the best option is to remove it.

2. Reset the Outlook navigation pane

The Outlook navigation pane serves as a hub for switching between different tabs, such as Mail, Calendar, People, and Tasks. An issue with the navigation pane can sometimes prevent the Outlook app from starting properly.

You can try resetting the navigation drawer to remove all customizations and see if that helps. Press Win + R to open the Run dialog box. Type Outlook.exe /resetnavpane in the box and press Enter .

3. Create a new Outlook profile

Outlook profile contains all email account related settings, including server configuration, signature, rules, and many other options. If the current profile is damaged or inaccessible, Outlook may not open and display an error. In most cases, you can fix such problems by creating and switching to a new Outlook profile.

To create a new Outlook profile:

1. Press Win + R to open the Run dialog box.
2. Type control in the box and press Enter to .
3. Click Mail (Microsoft Outlook) .
4. In Profiles , select Show Profiles .
5. Click the Add button , enter a name for the profile, and click OK .
6. Enter your account details and click Next to create your profile.
7. Select the new profile in When starting Microsoft Outlook and click Apply .

4. Run the Office repair tool

Microsoft Office repair tool on Windows can help you fix various Outlook errors. Here's how to run it.

1. Press Win + R to open the Run dialog box.
2. Type appwiz.cpl in the box and press Enter .
3. Select the Microsoft Office suite in the list and click the Change button at the top.
4. Select the Online Repair option and then click Repair .

5. Repair Outlook data files

Another reason why you encounter the "Cannot start Microsoft Outlook" error is because the data file is corrupted. Fortunately, Microsoft has integrated Inbox Repair Tool that can help repair these files. Here's how to run it.

1. Right-click the Outlook shortcut and select Properties .
2. In the Shortcut tab , click Open File Location .
3. Locate SCANPST.EXE and double-click it.
4. In the Microsoft Outlook Inbox Repair Tool window, click Browse and then navigate to the following folder:

C:Users*username*AppDataLocalMicrosoftOutlook

1. Replace *username* in the path above with your own username.
2. Select the profile you want to repair and then click Start .

Once the scan is complete, try opening the Outlook app again.

6. Turn off Compatibility Mode for Outlook

Compatibility Mode on Windows is a useful feature that helps you run older programs and software on your Windows PC. However, because Outlook is fully optimized for Windows, running it in Compatibility Mode can cause strange errors.

To turn off Compatibility Mode for Outlook, right-click the shortcut and select Properties . Switch to the Compatibility tab and uncheck the Run this program in compatibility mode option . Then, click Apply > OK. After this, Outlook will open on the Windows computer.

Applying one of these solutions will fix the "Cannot start Microsoft Outlook" error and help the email client work as expected. That said, if you're tired of dealing with such problems with the Outlook app, there are plenty of free email apps for Windows worth exploring.