Fix: Outlook not Responding

Microsoft Outlook is part of the flagship Office suite and is used as an email manager. Outlook is not limited to managing Outlook.com but instead, you can also sync other emails from third-party websites such as Yahoo, Gmail etc.

Microsoft Outlook not Responding

Despite active development in the Outlook application on PCs, users still face an issue every once in a while where their Outlook client refuses to connect to the remote servers and is stuck in a not responding loop. This issue is very common and occurs every now and then and doesn’t depend on the email address being used. In this article, we will go through all the causes and go through the solutions used to fix the issue.

What causes Outlook Not To Respond?

Outlook is the flagship email application by Microsoft and despite getting the spotlight by Microsoft itself, it is notorious for various different issues including the not responding issue. We checked various user reports and after replicating the same conditions on our test PCs, we came up with a list of causes which were causing the issue. Here are some of them:

  • Conflict with Outlook: If another third-party program is using or conflicting with Outlook, the application will not launch properly and display the not responding prompt.
  • Large Mailbox: The computer Outlook application is not optimized enough it seems to support large mailboxes. Large mailboxes are quite common if you have a work email connected with Outlook which flood the mailbox.
  • Corrupt Office Programs: Since Outlook is part of the Office Suite by Microsoft, they can get corrupt every now and then. The office suite is known for its share of problems and simply repairing the suite fixes the issue.
  • Antivirus Software: Antivirus software are installed to protect the user from malicious software but sometimes, they flag normal applications (false positive). We will check whether this is true by temporarily disabling the software.
  • Corrupt user profile: Each Outlook application is configured with a User profile. If that very user profile is corrupt, Outlook will not be able to read it properly and go into a non-responsive state.
  • Add-ins: Add-ins are very popular in Outlook and even though they tweak the user’s experience, they are known to cause various issues. Proper troubleshooting will be needed to solve this.
  • AddData Redirection: If your Application Data folder is pointing towards a Network Location, Outlook will not be able to load the contents properly. Fixing the redirection fixes the problem.

Before we move on with the solutions, make sure that you have backed up your account contents over the cloud and are logged in as an administrator on your computer.

Solution 1: Checking Outlook Usage by other Applications/Task

The very first thing which you should check is if Outlook is being used in the background either by another third-party application or it is performing a task. If this is the case, when you launch Outlook, it will already be busy and will go into a not responsive state. This is because of one distinct instance, you have launched another instance which directly conflicts with the first one.

Outlook being used in Background

Hence you should let the current task finish before you try to launch Outlook again for another one. For example, you should wait for the application to finish sending those bulk emails. You can easily check whether it is busy with another process by checking the taskbar at the bottom-right of the screen. An Outlook icon will be present. You can also open task manager and see if there are third-party applications running which are using outlook for their own operations.

Solution 2: Using Outlook in Safe Mode

There is an option in Office Suite where you can start the applications in a safe mode. In safe mode, Outlook disables all external add-ins and preferences and loads up with only the essential drivers. Hence if there were any problematic modules/add-ins, they would be disabled and the application would run perfectly.

First, you should check starting Outlook in Safe mode. If the applications work perfectly, you can move on to the next solutions and try troubleshooting where the problem lies.

  1. Press Windows + R, type “outlook /safe” and press Enter.
Outlook Safe Mode
  1. Now Outlook will ask you to select the profile which you want to load up. Select the correct profile and click OK.
Selecting Outlook Profile
  1. Now check if Outlook is working perfectly.

Solution 3: Repairing Outlook (Through Office Suite)

In the majority of the cases, the reason why users face Outlook being unresponsive is because the installation files of Microsoft Office are either corrupt or have missing modules. If the installation itself isn’t complete or in a working state, you won’t be able to use individual office applications properly such as Outlook. We will try to repair the application through the application manager and see if this works for us.

  1. Press Windows + R, type “appwiz.cpl” in the dialogue box and press Enter.
  2. Once in the application manager, locate the entry of Microsoft Office. Right-click it and select Change. If there is an option of Repair here, you can click it directly.
Changing Installation of Office Suite
  1. Select the option of Repair from the following windows and press Continue.
Repairing Office Installation
  1. Now follow the on-screen instructions and when the process is complete, restart your computer and check if you can launch Outlook without any issues.

Solution 4: Repairing Outlook Files

If you are importing Outlook Files, it is possible that the files you are using are corrupt or incomplete. Files can get into this state every once in a while and get issues in their contents mostly when they are moved or during transmission. In this solution, we will try to repair the Outlook files and see if there are any error present. If there are, the automatic repair tool will fix them and inform you accordingly.

  1. Press Windows + E to launch the Windows Explorer. Once in the explorer, navigate to the following file path:
C:\Program Files (x86)\Microsoft Office\root\Office16
  1. Now search for SCANPST.EXE, right-click on it and select Run as administrator. Now once the scanner is opened, click on Browse and navigate to the .pst file which you are using so it can be scanned.
Running Outlook Scanner
  1. Now click on Start. The scanning process will now begin. If there are any discrepancies present, the scanner will inform you accordingly. Even if you find minor issues, it is recommended that you fix them. Click Repair to repair the files. Make sure that you check the option Make a backup of scanned file before repairing so you always have a copy if things go sideways.
Repairing Outlook Files
  1. After the repairing process, restart your computer and check if the issue is resolved.

Solution 5: Updating Outlook and Windows

Microsoft pushes updates to both Windows and Outlook to solve various bugs and issues and to also introduce new features. If by any chance you are avoiding the updating process, it is recommended that you do not delay it and get everything updated as soon as possible. We recommend that you backup your data before proceeding. Also, make sure that you have closed all the programs running in the background before proceeding. Windows Updates sometimes ask for a restart to apply the changes.

  1. Press Windows + S, type “update” in the dialogue box and open the Update settings application.
  2. Now in the next window, click on Check for updates so the computer can connect to the Microsoft servers and see if there is an update pending for your machine.
Checking for Updates – Windows Update
  1. Restart your computer properly after updating your Windows to the latest build.

After Windows has been updated, we will update Outlook to the latest version. Follow the steps below.

  1. Click the File option present at the top of the Outlook application.
  2. Now select Office Account from the left navigation pane. Click on Update options from the right side of the screen and select Update now.
Updating Outlook
  1. Now the update process will begin and new updates (if any) will be installed.

Note: In newer versions of Windows, Microsoft Office (including Outlook) is updated through Windows update itself so you just have to update your Windows to the latest build.

Solution 6: Updating Outlook Version

As you all might already know, Microsoft automatically stops support of older versions of the Office applications after its support period ends. It came to our reports that the not responding issue mostly occurs on older versions of Office. This is because the older versions don’t get many updates and are mostly obsolete with the majority of the users using newer versions of the application.

Office 2013

If you have an older version of Office (including Outlook), we recommend updating it to at least 2013. Office 2013 is to date (when writing this article) the most used copy of the Office suite. Make sure that you have your product key at hand as you will be asked to enter it after you download the newer version in your computer. Also, make sure that you have backed up your files to an accessible location before proceeding.

Solution 7: Deleting Email Accounts

The Email accounts which you add in the Outlook application automatically get added in the computer’s list of email accounts. All the storage is then synchronous including all the attachments and the media files. If any of the email accounts is causing issues or have incomplete/corrupt files, you will face the not responding error. In this solution, we will navigate to the email settings and delete all the email accounts associated with Outlook. Make sure that you have the credentials as you will be asked to enter them later on.

  1. Press Windows + R, type “control” in the dialogue box and press Enter. Once in the control panel, search for “mail” and open the application which returns in the results.
Mail Settings in Outlook
  1. Now click on Email Accounts from the next window which follows.
Email Accounts – Mail options
  1. Now under the tab of Email, select each email accounts one by one and click on Remove. Do this for all email addresses.
Removing Registered Email Accounts
  1. Now click on Close and restart your computer. Now launch Outlook again and check if the issue is resolved.

Solution 8: Disabling Antivirus Software

There have been numerous reports that Antivirus software like Semantic or Norton causes permissions or access issues. These Antivirus software try to protect your personal files and folders by making sure they are not changed by other software or users even if the parent applications (such as Outlook) are making changes to them.

In some cases, they give a false positive and block access to the document even if can be saved by you naturally. There are several features which Antivirus software implements such as File Protection in Semantic. McAfee even released official documentation about this and claimed to fix it in one of their updates. You should try updating your Antivirus software and if that doesn’t work, you can check our article on How to Turn Your Antivirus Off.

Solution 9: Disabling Add-ins

One of the leading factors due which Outlook gets into a ‘not responding’ state is where third-party add-ins are loaded onto the software while they are not even supported. You can disable all the add-ins one by one and troubleshoot which one might be causing the problem. You can remove it permanently afterward.

  1. Open Outlook and click “File” present at the top-left side of the screen.
  2. Now click on the tab “Options” present at the navigation bar on the left side of the screen.
Opening Outlook Options
  1. Select the tab “Add-ins” on the left navigation pane. All the add-ins will now be listed on your right. Disable all third-party add-ins and restart Word after ending it properly using Task Manager.
Add-ins – Outlook Options
  1. Now check if the problem at hand got solved after restarting Outlook completely.

Solution 10: Reinstalling Outlook

If all the above methods don’t work, you can go ahead and completely reinstall the Outlook application. The Outlook application is bundled with other Office applications so make sure that you are free of using these applications during the reinstallation process. Also, make sure that you have your Office credentials at hand before proceeding as you will be asked to input them again when you are installing a new package.

  1. Press Windows + R, type “appwiz.cpl” in the dialogue box and press Enter.
  2. Once in the application manager, search for Microsoft Office, right-click on the application and select Uninstall.
Uninstalling Outlook
  1. Now either insert the Office installation CD or navigate to the official Office website and download a fresh copy. After the installation, restart your computer before launching Outlook.

Kevin Arrows


Kevin is a dynamic and self-motivated information technology professional, with a Thorough knowledge of all facets pertaining to network infrastructure design, implementation and administration. Superior record of delivering simultaneous large-scale mission critical projects on time and under budget.

Expert Tip

Fix: Outlook not Responding

If the issue is with your Computer or a Laptop you should try using Reimage Plus which can scan the repositories and replace corrupt and missing files. This works in most cases, where the issue is originated due to a system corruption. You can download Reimage by clicking the Download button below.

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