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MS Outlook is the well-known email manager that you can purchase separately from the Office 365 subscription or buy a profession subscription in which Outlook is a member. After installing the software, you will want to add accounts in it. On a rare occasions, the application may decline to open and show ‘failed to launch’ error. Sometimes, Windows 10 users face such error more for Office 365 applications.

Reasons for Outlook Error “Failed to launch”

Based on users’ experiences, it appears that the problem may occur due to:

  • Troubles with the Office application
  • Corruption in the Outlook profile
  • Outlook Data File (.ost/.pst) is damaged
Instant Solution

Recommended tool to solve Outlook issues. Try Kernel for Outlook PST Repair to repair and recover data from corrupt PST files.

Sometimes, other reasons like new program installation containing viruses can contribute to the corruption of PST files. Currently, repairing Outlook 365 on Windows 10 is a real problem if you use it for official emails daily. In this article, we have mentioned some methods that will help you to repair Outlook Office 365 on Windows 10.

Methods to Repair Outlook 365 Installed on Windows 10
Method 1: Using Microsoft Quick Repair

Microsoft provides a free Office 365 troubleshooting tool that can resolve most of the common problems related to Office 365 applications. However, it might not be helpful in addressing all the issues associated with Office 365 applications, but common issues like Outlook or any other app not working properly can be fixed easily. Follow the steps given below:

  1. Go to the Start menu and click the Setting icon to open the Settings or type Settings in the search bartype Settings in the search bar
  2. Select Apps & features to display all the installed apps on your Windows 10.Apps & features
  3. Find the Microsoft 365 app and click on it to see the available options. You will see two options – Change and Uninstall. Click the Change button to repair Office 365.Click Change button to repair Office 365
  4. Now you can see the User Account Control Prompt will appear on the screen. Click Yes to open the repair dialog box.
    Note: There are two ways to fix Office 365 apps – Quick Repair and Online Repair. The Quick Repair will fix the common issues quickly. At the same time, Online Repair involves reinstalling Office 365 apps to fix all the problems with Office 365 apps. Here we will perform both the repairing methods.

    • Select Quick Repair and click Repair. In the confirmation window, click Repair to start the repairing process.Select Quick Repair and click Repair
    • The repair process will be quick. Finally, a notification will appear on the screen.
  5. If you choose the Online Repair method, you might lose the Office 365 customization and settings.
    • Select Online Repair and click Repair. A notification will appear: “We’ll download files to repair your installation.” Click Repair to start the repairing process.
    • After completing the Online Repair process, the “Office 365 is installed now” message will appear on the screen. Click Close to end the process.
    • Now, open Outlook on your system and enter the email address to which Office 365 is subscribed. A copy of the Office app will be activated on your Windows 10. You can also activate Office 365 with the product key.
Method 2: Uninstall & Reinstall Outlook 365

If your Outlook 365 application is not working properly, you can try uninstalling and reinstalling it. This will help you to get rid of any corrupt files that might be causing the problem.
Here are the steps that you need to follow to uninstall and reinstall Outlook 365 on Windows 10:

  1. Close the Outlook 365 application if it is open.
  2. In the Run window, type “appwiz.cpl” & click OK.Run window
  3. In the Programs and Features window, find Microsoft Office 365 from the list of installed programs and click on it.
  4. Click on the Uninstall button.Click on the Uninstall
  5. Follow the prompts to complete the uninstallation process.
  6. Once the uninstallation is complete, restart your PC.
  7. Download and install the latest version of Outlook 365 from the Microsoft website.
  8. Launch Outlook 365 and enter your login credentials. Your account should now be working properly.
Method 3: Repair Office 365 Using Microsoft Fix It

If uninstalling and reinstalling Outlook 365 does not fix the problem, you can try repairing it using the Microsoft Fix It tool. This tool will automatically fix any corrupt files that might be causing the issue.
Here are the steps that you need to follow to repair Outlook 365 using Microsoft Fix It:

  1. Download the Microsoft Fix It tool.
  2. Double-click on the downloaded file to run it.
  3. Click on the Run button.
  4. Follow the prompts to complete the installation process.
  5. Once the installation is complete, launch the program.
  6. Click on the Start button.
  7. Follow the prompts to complete the repair process.
  8. Restart your computer and launch Outlook 365. Your account should now be working properly.
Method 4: Change Your Firewall Settings

If you are using a third-party firewall application, then it might be blocking Outlook 365 from accessing the internet. You can try changing your firewall settings to see if that fixes the problem.
Here are the steps that you need to follow to change your firewall settings:

  1. Access the Run dialog box with Windows + R Keys.
  2. In the Run dialog box, type “firewall” and click OK.type firewall
  3. In the Firewall window, click on the Allow a app or feature through the Windows Defender Firewall option.Allow a program
  4. Scroll down the programs list and find Microsoft Outlook. If it is not on the list, click on the Change Settings on the Change Settings button
  5. Browse for Microsoft Outlook and click on it.Browse for Microsoft Outlook
  6. Click on the Add button and hit OK.
  7. Restart your computer and launch Outlook 365.

See it’s very simple to repair Outlook 365 application on your Windows 10. However, it’s not necessary that there is always a problem with the Outlook app. Sometimes, the PST file in Outlook 365 gets corrupt, which doesn’t allow the app to work properly.

So, to deal with this issue, you’ll have to repair the corrupt PST file.

Method 5: Automated Solution to Repair Outlook PST

There are many solutions available to repair PST files, but the Kernel for Outlook PST Repair tool stands out from the crowd. It is a great Outlook repair tool to repair and recover data from corrupt PST files. Using this tool, one can easily repair and recover encrypted password-protected files. And you can save recovered PST data to DBX, MBOX, MSG, EML, TXT, RTF, HTML, and MHTML formats It allows users to repair even large-sized PST files that are often not compatible with other tools.

Also, you can recover permanently deleted items and attachments from Outlook with the help of this Outlook repair tool. You can even migrate PST files to Office 365, email servers, and web email clients with the help of this software.


I hope you find this article helpful. Outlook is an essential application for organizations and individuals and is available with Office 365 subscription. When this application stops working, it can delay the work. Therefore, it is highly important to get rid of such errors. Outlook 365 is a great email client, but sometimes things go wrong. We have outlined the best methods for repairing Outlook 365 on Windows 10. Hopefully, one of these solutions will help you get your email client up and running again.

All these methods are effective in resolving the issue. But if you are still facing problems with your Outlook 365, do not hesitate to use our recommended tool as it has excellent features that can help you repair your corrupt or damaged PST files easily. The trial version of the software is also available for free download, so you can try it before purchasing the full version. Get Started Today!! Using the manual methods, you can quickly fix the errors with Outlook 365 application but using the professional solution is like going for the best. As a tech writer, I will highly suggest to try the repair tool to experience the change. We certainly have more insights coming your way. So, stay connected with our blog page.

Kernel for Outlook PST Repair