How to Fix Outlook Not Responding?

Ever had problems with Outlook not responding? Well, you probably have, …. it’s a common problem that many users face. Fortunately for you, all the solutions you need are right here.

Mar 20,2020 • Filed to: Recoverit Topic • Proven solutions


Q:What to do if Outlook is not opening?

I am in a middle of a conversation with an important client, I am close to sealing a sweet deal and as I am about to send the email, Outlook freezes! It stops responding! Oh No! What do I do? Help! Somebody! Anybody! Please! SAVE MY SOUL.

Microsoft Outlook is subscription based application that is installed on a user’s computer and configured to send and receive mails from your computer. It can also be used to manage several types of personal data including calendar appointments and related entries, tasks, contacts, and notes.

Part 1: Why is Outlook not responding?

Microsoft Outlook belongs to the class of software referred to as ‘’Email Clients’’

These class of software are programmable email tools that are installed on your computer to send and receive emails from it. This is in contrast to ‘’Webmail’’ that allow users access emails via web browsers.

Microsoft Outlook is certainly one of the most flexible ‘Email Client’’ tools available today and this might understandably be the reason why organizations all over the world use it to manage their emails.

Microsoft Outlook like any other software is also susceptible to bugs and problems and these problems, when they occur, are usually frustrating and in most cases stop you in your tracks.

One of the most common problem that users often face is the “Outlook not responding” error. This message is commonly displayed when Windows is not able to communicate quickly enough with a program running on your computer.

Against this backdrop, a list of possible reasons that might cause Microsoft Outlook to stop responding have been detailed for you below.

iii. Double-click the SCANPST.EXE file to open the Microsoft Outlook Inbox Repair tool.


iv. Click the Browse button.

v. Find the .pst file you want to repair and click the open button

vi. Click the Open button.

vii. Click the Start button.


viii. As a precaution, tick the Make a backup of scanned file before repairing then click the repair button.


Once you click the repair button, the Outlook Inbox Repair Tool will scan and repair the .pst file for the email account with problems.

Once the repair is completed, you should launch Outlook to confirm if all the issues with the account have been resolved.

g. Turn off the Anti-Virus Software

An out-of-date antivirus program may sometimes cause errors when you try to start Outlook as there may be compatibility issues between your antivirus program and Outlook. Sometimes, the issue may be due to the fact that a file that you are trying to open has been infected with a virus and your antivirus program has been unable to remove it.

In these instances, the best option is to update your Anti-virus software. Please note that turning-off your Anti-virus software to troubleshoot Outlook errors should always be the last resort as it can always leave your system vulnerable to multiple threats.

h. Create a New Outlook Profile

You could create a new profile in Outlook when faced with ‘’not responding errors’’ A new profile is also advised when you upgrade to a newer version of Outlook.

Follow the steps below on how to create a new profile for Outlook.

i. Close Outlook if it is already running.

ii. Open Control Panel and locate the Mail applet.

iii. Select the Show Profiles button.


iv. Click the Add button to make a new profile


i. Organize and Archive Old Data

Your Outlook mailbox has a limited size and to stop it from filling up with content and possibly creating problems, you should archive old items by doing the following:

i. Click File > Info > Tools > Clean up old items


ii. Click the Archive this folder and all subfolders option, and select the folder you want to archive.


iii. Beside the Archive items older than option, enter a date you want.

iv. Select the Include items with “Do not Auto Archive” checked box and click ok.

Part 3: Fix Specific Not Responding Issues

1. Outlook Keeps Crashing.

Whenever Outlook abruptly and endlessly closes whenever it is opened, this indicates a possible conflict with Outlook and other applications, a corrupt file within outlook or that the application has been wrongly set-up. You could attempt to rectify the errors by trying the following actions below:

a. Restart your computer

Some programs running in the background of your computer may conflict with Outlook and cause it to crash. You could try restarting your computer and then reopening Outlook to see if it runs correctly.

b. Rectify issues caused by interference of Add-ins

Add-Ins that improve user-experience may sometimes create problems due to incompatibility issues.

i. Close Outlook and press Window logo + R keys to open a Run dialog box.

ii. Once it opens, input Outlook /safe in the textbox and then click OK.


iii. if the issue is fixed, launch Outlook and navigate to File > Options > Add-Ins.

iv. Find and select COM Add-ins and click on the Go button.


v. Next, clear all the checkboxes in the list and then click on the OK button to save your settings.

vi. Restart Outlook in order to confirm if the issue have been resolved.

c. Run Outlook Diagnostics

If Outlook keeps crashing, you can run the Outlook Diagnostics Tool to scan and fix common issues related to Outlook.

i. Download the Outlook Diagnostics Tool from Microsoft's official website and run it. Launch it and it will automatically scan and attempt to fix the issues.

2. Outlook Stuck on Processing.

a. Outlook in use

‘’The file ...ost is in use and cannot be accessed” error message displayed by Outlook is indicative that the Outlook OST file is being used by another program. There could also be other reasons that cause such error to be displayed such as synchronization issues between the OST and associated Exchange mailbox or multiple users in a networked environment trying to access the same OST file. To resolve the issue, follow the steps below:

i. Close Outlook if it is already running.

ii. Open Task Manager and select the “Processes” tab

iii. In the list, look for “Outlook”, “LYNC”, “Communicator”, or “UCMAPI” named processes

iv. Select such processes and hit “End Task” button one at a time.

b. Problems from external contents

Microsoft Office is configured by default to block external content—such as images and linked media. For this reason, problems may arise if Outlook downloads some external contents which are not required. To prevent Outlook from downloading external contents, you should do the following:

i. Go to file


ii. Select options and then click the Trust Center option.


iii. Click on Automatic Download.


iv. Finally, click on, Don't download pictures or other content automatically in HTML e-mail option.

c. Mailbox is too large

Your Outlook mail box can get considerably large if you send and receive a lot of emails. This becomes a problem as the larger the mailbox becomes, the longer it takes for Outlook to process it which invariably increases the possibility of errors. To reduce the size of your mailbox, run the Mailbox Cleanup tool:

i. Click the file tab.

ii. Click Tools and then Mailbox Cleanup.

iii. Select the following folders: View Mailbox size, Find items older than, View deleted items size and Empty deleted items


iv. Select Empty conflicts to perform the cleanup task.

d. AppData folder is being redirected to a network location

Outlook has numerous app data to perform different types of operations and if it happens that your network connections are sluggish, Outlook has to wait for read and write operations to the AppData directory to finish. To stop this from happening you should disable the redirection of the App Data directory.

i. Click the file tab to start Outlook.

ii. Start Registry Editor by Pressing the Windows Key+R to open a Run dialog box. Type regedit.exe, and then press OK.

iii. In Registry Editor, locate and then click the following sub-key:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders

iv. Locate and then double-click the following value: AppData

v. In the Value data box, type %USERPROFILE%\AppData\Roaming

vi. Click OK and exit Registry Editor

e. Outlook is dealing with a large or long process

When the size of your Outlook data file reaches 10 gigabytes (GB) or exceeds it, the application routinely pauses. This problem can however be resolved by reducing the size of your Outlook data file by moving or archiving items from the file.

f. A dialog box is being opened

This can occur when there is no user information specified for your version of Office. To resolve it, you must fill in the user information by carrying out the following:

i. Click File-> Options-> General-

ii. Under the ‘’personalize your copy of Microsoft Office’’ section, fill the User name and Initials section.


3. Scanpst File Not Responding

Stellar Repair for Outlook is an advanced PST recovery software which instantaneously restores corrupt Outlook PST files with a very high rate of success. Its potent scan engine can analyze severely corrupt PST file of any size to recover mailbox data including deleted emails, attachments and contacts. Once you download the software from, install it and follow the instructions below to use it.

i. Click 'Find Outlook File' or 'Select Outlook File' options in order to start the repair.


ii. Click the ‘Find Outlook File’ option and then click the ‘Look In’ option and then choose the drive name where damaged PST files are located.


iii. Select all corrupt PST files to start scanning by clicking the start button.


iv. After the Selected PST files are successfully repaired, click on any item from the tree on the left side.

However, if you encountered other issues like Outlook not opening, learn how to fix Outlook not opening here.

Closing Words

Emails have been with us since 1972 when Ray Tomlinson sent the first Email and since then, ever more efficient ways of sending and receiving mails have been developed.

At the forefront of this innovation is Microsoft Outlook; an indispensable Email Client for businesses and individuals that has stood the test of time.

Although, not without its disadvantages, the sheer versatility of this universally acclaimed product undoubtedly gives it an edge over its competitors.

Amy Dennis

staff Editor

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