How to Deal with ‘Microsoft Outlook Not Responding’ Error?

Microsoft Outlook is undoubtedly one of the most versatile email client tools available today, and this is right why it is used worldwide by organizations of all sizes. But like any other software, Outlook is also prone to bugs and problems”10 Common Outlook Problems

As a user, these problems can sometimes be frustrating. One common problem that crops up often is “Outlook not responding” or Outlook Not Working error. To help you fix this error and to reduce your frustrations, we have put together a comprehensive article that will give you all the answers to your questions.

How does this problem affect Microsoft Outlook Users?

When an application or process gets stuck in operation or reaches a deadlock for resources, the “not responding” message appears on the title bar of the application’s window. This is common across all applications on a Windows machine.  Most of the time, the best option is to wait it out, even it is frustrating for you!

When this happens to your Outlook, the stakes are much higher because there is always a possibility for you to be in the middle of a conversation with a potential client. Or worse, you could be expecting an update for a crucial security issue and your Outlook stops working.

When you try to click anywhere on the Outlook window, the entire screen becomes translucent with the message “Microsoft Outlook not responding” displayed on the title bar.

Frustrating, right? Well, all is not lost and here are some things you can do to fix

How to Fix the “Outlook not responding” error:

The below-mentioned solutions work to fix issues in Outlook 2007, 2010, Outlook 2013 and Outlook 2016.

1. Quit Outlook and all related processes through Task Manager

outlook not responding

If an existing Outlook process is stuck in operation, a fresh instance of the application cannot be initiated successfully. This is because one or more ‘outlook.exe’ processes would be running in the memory when you’re trying to start another ‘outlook.exe’ process, thereby creating a conflict.

Thus, one of the first things to try out is to kill all ‘outlook.exe’ processes through the Task Manager. For this:

  1. Right-click on the taskbar and click on “Task Manager”; you may also open it directly by pressing Ctrl + Alt + Del from the keyboard.
  2. Click on the Processes tab and search for all processes with the word Outlook in their name (primarily, processes named outlook.exe)
  3. For each process you find, select it by clicking on it once and then click on the ‘End Process’ button at the bottom right corner of Task Manager

This should kill all the Outlook processes. Try restarting your Outlook to see if the issue is fixed. If still your outlook not working, follow the guide below; 

2. Identify and remove the problematic Outlook add-ins

outlook not responding

Add-ins and customization files are installed into Outlook to improve the user experience. However, sometimes, faulty add-ins can cause problems with the normal working of Outlook. Hence, that’s where you should look next.

Here’s how you can spot if add-ins are creating the issue:

  1. Start Outlook in safe mode by pressing down the Ctrl key and clicking on Outlook icon; you may also launch Outlook in safe mode by opening the command prompt and typing outlook.exe /safe.

Note:  Launching Outlook in safe mode loads Outlook without any add-ins or customisation files.

  1. If Outlook launches successfully, try to send/receive emails or do any other task to ensure that add-ins are the problem.
  2. To find which add-in is faulty, go to File -> Options -> Add-ins -> Go
  3. Due to the safe mode, all add-ins will be unchecked. One by one check add-ins and keep restarting Outlook with each check. Wherever Outlook doesn’t start correctly, that add-in is your culprit.

3. Turn off the Antivirus Program

Antivirus software is meant to safeguard your computer from all threats. Some of the products are designed in such a way that they scan every outgoing and incoming email to your system to detect problems. This might cause problems with the normal functioning of Outlook at times. Plus, your antivirus may flag some add-ins as untrustworthy and could even block them, thereby causing Outlook to hang or crash.

Go to Control Panel and turn off your antivirus. Restart Outlook and check. If everything works fine, you know where the problem is. To keep using both your antivirus and Outlook without issues, add Outlook and all its add-ins (that you trust) to the list of trusted applications in the antivirus software.

4. Organize and Archive Stuff

In order to function smoothly, Outlook needs to be organized and cleaned up every few weeks. So, make sure you organize all emails in separate and properly labelled folders instead of a single huge one. Also, delete all old emails that are no longer required. This also includes emptying the Outlook Deleted Items folder. In addition to these basic steps, you should archive old important emails in order to free up some space within the Outlook data file.

5. Reduce Outlook Data File Size

Outlook stores all data in the Personal Storage Table or.PST files. But when used with Exchange mailboxes, the data is stored in OST files (.ost) as well. If your Outlook PST or OST files grow too large in size, they are prone to damage and corruption.

Outlook not responding

Hence, clean up your Outlook inbox and other folders, archive old emails, and empty the Deleted Items folder to reduce the size of Outlook data files. Moreover, you can use Outlook Compact feature to compress data files and reduce their size.

6. Repair & Update Outlook

Outlook not responding

If none of the above-mentioned solutions works, there might be an issue with your Outlook installation. To fix such issues:
a.  Go to Control Panel and find MS Office in the installed programs
b.  Right-click on it and select Change
c.  Click on Repair -> Continue
d.  Follow the subsequent instructions


Once the repair is complete, check for any Outlook service-packs or other updates your installation is missing and if there are any, download and install them. You can also refer to this Manual


To conclude, “Microsoft Outlook not responding” or Outlook not working error is not only frustrating but is also cryptic. This means, finding the cause of the problem and its solution is not easy. Try the above resolutions to see which one resolves the issue for you.

If nothing works, Outlook PST file might have been corrupted or severely damaged. Repair it using a trusted PST repair software called Stellar Repair for Outlook Technician. The product will help you fix issues within the corrupted PST and will also extract all data from it to store in a fresh new PST that you can directly import into Outlook. Apart from this you can Split or compact PST file to avoid the error due to oversize PST File.

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Also Read:

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Outlook Search not working

Top 5 Outlook Problems

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Outlook Stuck on Loading Profile

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