"Outlook not responding" error or Outlook freezes when you open a file or send mail
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Microsoft Outlook 2013
Microsoft Outlook 2010
Microsoft Outlook 2010 with Business Contact Manager
When you open a file or send an email message in Microsoft Outlook 2010 or later versions, Outlook freezes, or you receive the following error message:
Outlook not responding
This problem occurs for one or more of the following reasons:
You have not installed the latest updates.
Outlook is in use by another process.
Outlook is loading external content, such as images in an email message.
A previously installed add-in is interfering with Outlook.
Your mailboxes are too large.
Your AppData folder is redirected to a network location.
You have to repair your Office programs.
Outlook data files have become corrupted or damaged.
Your installed antivirus software is outdated, or it conflicts with Outlook.
Your user profile has become corrupted.
Another program conflicts with Outlook.
Note This issue may occur for one or more of the reasons in the "Cause" section. To fix this issue, you may need to follow one of several of the following troubleshooting steps. These steps are provided in a specific order based on how commonality and complexity, please follow these steps in the given order.
The Office installation on your computer might not be up-to-date. This might be because Windows Update is not configured on your computer to automatically download and install recommended updates. By installing important, recommended, and optional updates, you can often correct problems by replacing out-of-date files and fixing vulnerabilities. To install the latest Office updates, click the link for your version of Windows, and then follow the steps in the article:
Performance may be decreased if you use the Outlook AutoArchive feature or sync to Outlook with a mobile device. This is because these processes can use a large number of resources.
If Outlook is in use by another process, this information is displayed in the status bar at the bottom of the screen. If you try to perform other actions while Outlook is in use, Outlook may not respond. Let the task in process finish its job before you try another action.
Although add-ins can enhance your user experience, they can occasionally interfere or conflict with Outlook. Try to start Outlook without any add-ins running.
How to start Outlook without add-ins
Do the following, as appropriate for your operating system:
If you are running Windows 8, swipe in from the right edge of the screen, and then tap Search. (If you are using a mouse, point to the upper-right corner of the screen, move the mouse pointer down, and then click Search.) Type Run in the search box, and then tap or click Run.
If you are running Windows 10, Windows 7 or Windows Vista, click Start.
If you are running Windows XP, click Start, and then click Run.
Type Outlook.exe /safe, and then click OK.
If the problem is resolved, click Options on the File menu, and then click Add-Ins.
Select COM Add-ins, and then click Go.
Clear all the check boxes in the list, and then click OK.
If the problem does not occur after you restart Outlook, one of the add-ins is likely the cause of the problem. Restore the add-ins one at a time until the problem does occur to determine which add-in is causing the problem.
As your mailbox size increases, more resources are required to open each folder. If you have a large number of items in any single folder, you may experience performance issues during certain operations. See the following articles for more information:
Outlook stores certain data, such as email signatures and the spelling checker dictionary, in the AppData folder. If the network is performing slowly, Outlook must wait for read and write operations to the AppData directory to finish.
How to disable redirection of the AppData directory
Start Registry Editor. To do this, use one of the following procedures, as appropriate for your version of Windows:
Windows 10 or Windows 8: Press Windows Key+R to open a Run dialog box. Type regedit.exe and then press OK.
Windows 7: Click Start, type regedit.exe in the search box, and then press Enter.
In Registry Editor, locate and then click the following subkey:
When you install Outlook, an Inbox repair tool (scanpst.exe) is also installed on your PC. The Inbox repair tool can resolve problems by scanning your Outlook data files, and repairing errors. To use the Inbox repair tool, exit Outlook, and then follow the steps in the following Office article:
If your antivirus software is not up-to-date, Outlook may not function correctly.
How to check whether antivirus software is up-to-date
To keep up with new viruses as they are created, antivirus software vendors periodically provide updates that you can download from the Internet. Download the latest updates by visiting your antivirus software vendor’s website.
How to check whether antivirus software conflicts with Outlook
If your antivirus software includes integration with Outlook, you may experience performance issues. You can disable all Outlook integration within the antivirus software. Or, you can disable any antivirus software add-ins that are installed in Outlook.
Important When you change your antivirus settings, this may make your PC vulnerable to viral, fraudulent, or malicious attacks. We do not recommend that you try to change your antivirus settings. Use this workaround at your own risk.
You may have to contact your antivirus software vendor to determine how to configure the software to exclude any integration with Outlook or to exclude scanning in Outlook.
When you start Windows normally, several applications and services start automatically and then run in the background. These applications and services can interfere with Outlook. A Selective Startup or "clean boot" process can help you identify problems that are caused by application conflicts.
If you use the Selective Startup option in System Configuration, you can turn services and startup programs on or off individually to check whether the problem occurs the next time that you start your computer. In System Configuration, if you select a check box, the related service or startup program runs when you restart the computer. If the check box is cleared, the service or startup program does not run when you restart the computer.
Follow this procedure to use the process of elimination to identify the problem in Windows 10, Windows 8, Windows 7, or Windows Vista.
Note If you are using Windows XP, see the following Knowledge Base article:
Your user profile is a collection of settings that let you customize the computer appearance and performance. It contains settings for desktop backgrounds, screen savers, sound settings, and other features. User profiles help make sure that your personal preferences are used when you log on to Windows.
To determine whether this problem is caused by a corrupted user profile, create a user profile to see whether the problem still occurs when you use the new profile.
How to repair a corrupted user profile in Windows 8
Step 1: Create a user account
To create a user profile, you must first create a user account. When the new account is created, a profile is also created.
Swipe in from the right edge of the screen, and then tap Search. (If you are using a mouse, point to the upper-right corner of the screen, move the mouse pointer down, and then click Search.) Type Command Prompt in the search box, right-click Command Prompt, and then click Run as administrator.
Note If you're prompted for an administrator password or for confirmation, type the password or provide confirmation.
Type net user UsernamePassword /add, and then press Enter.
Step 2: Copy old files to the new user profile
After you create the profile, you can copy the files from the existing profile.
Note You must have at least three user accounts on the computer to complete these steps. This includes the new account you just created.
Log on as a user other than the user that you just created or the user that you want to copy files from.
In Control Panel, click Appearance and Personalization, and then click Folder Options.
Click the View tab, and then click Show hidden files, folders, and drives.
Clear the Hide protected operating system files check box, click Yes to confirm, and then click OK.
Open File Explorer. To do this, Swipe in from the right edge of the screen, and then tap Search. (If you are using a mouse, point to the upper-right corner of the screen, move the mouse pointer down, and then click Search.) Enter File Explorer in the search box, tap or click Apps, and then tap or click File Explorer. Type Command Prompt in the search box, right-click Command Prompt, and then click Run as administrator.
Locate the C:\Users\Old_Username folder, in which C is the drive that Windows is installed on, and Old_Username is the name of the profile that you want to copy files from.
Select all the files and folders in this folder, except the following files:
On the Edit menu, click Copy.
Note If you don't see the Edit menu, press Alt.
Locate the C:\Users\New_Username folder, in which C is the drive that Windows is installed on, and New_Username is the name of the user profile that you created earlier in this method.
On the Edit menu, click Paste.
Log off, and then log back on as the new user.
Note If you have email messages in an email program, you must import your email messages and addresses to the new user profile before you delete the old profile. If everything is working correctly, you can now delete the old profile.
If the information in this Knowledge Base article does not help resolve your problem in Outlook 2016, Outlook 2013 or Outlook 2010, see the following resources for more information: