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- Your installed antivirus software is outdated, or it conflicts with Outlook.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.
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.
To resolve this problem, make sure that your computer meets the Outlook 2016 system requirements
, Outlook 2013 system requirements
or Outlook 2010 system requirements
. Then, try the following steps in the given order.
Step 1: Install the latest updates
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 By installing important, recommended, and optional updates, you can often correct problems by replacing out-of-date files and fixing vulnerabilities.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:
Step 2: Make sure that Outlook is not in use by another process
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.
Step 3: Check the problem which caused by external contents
To resolve this issue, use one of the following methods:
- Prevent Outlook to download external contents. To do this, go to File>Options>Trust Center>Automatic Download, select the following two options:
- Don't download pictures or other content automatically in HTML e-mail option.
- Warn me before downloading content when editing, forwarding, or replying e-mail.
- Avoid sending such an email with external source.
Step 4: Investigate possible add-in issues
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.
- Restart Outlook.
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.
Step 5: Check whether your mailbox is too large
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:
We recommend that you move several items in your larger folders to separate folders, or that you archive those items by using the AutoArchive feature.
How to create a folder
- On the Folder tab, click New Folder in the New group.
- In the Name box, enter a name for the folder.
- In the Select where to place the folder list, click the location for the new folder.
Note The new folder will become a subfolder of the folder you select.
- Click OK.
To manage your mailbox by reducing the size of the Outlook data file, see Reduce the size of Outlook Data Files (.pst and .ost)
To manage your mailbox by using the AutoArchive feature, see AutoArchive settings explained
Step 6: Check whether your AppData folder is being redirected to a network location
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
- Exit Outlook.
- 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:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders
- Locate and then double-click the following value:
- In the Value data box, type the following path, and then click OK:
- Exit Registry Editor.
Step 7: Repair Office programs
You can automatically repair your Office program files to resolve such problems as Outlook freezing or not responding.
How to automatically repair Office
- Exit any Microsoft Office programs that are running.
- Open Control Panel, and then open the Add or Remove Programs item (if you are running Windows XP) or Programs and Features (if you are running Windows 10, Windows 8, Windows 7, or Windows Vista).
- In the list of installed programs, right-click Microsoft Office 2016, Microsoft Office 2013 or Microsoft Office 2010, and then click Repair.
If you are using Office Click-to-Run, follow the steps in the following Office article to repair Office Click-to-Run:
Step 8: Repair Outlook data files
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:
Step 9: Check whether antivirus software is up-to-date or conflicts with Outlook
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.
For a list of antivirus software vendors, see Consumer security software providers
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.Note
If you also plan to perform file-level virus scanning of .pst, .ost, Offline Address Book (.oab), or other Outlook files while Outlook is in use, see Plan antivirus scanning for Outlook 2010
orPlan antivirus scanning for Outlook 2013
Step 10: Create a user profile in Outlook
To create a user profile, follow these steps:
- In Control Panel, click Programs, click User Accounts, and then click Mail to open Mail items.
- Click Show Profiles.
- Select the profile that you want to remove, and then click Remove.
- Click Add.
- In the Profile Name dialog box, type a name for the profile.
- Specify the user name, the primary SMTP address, and the password. Then, click Next.
- You may receive the following prompt:
Allow this website to configure alias@domain server settings?In this prompt, select the Don’t ask me about this again checkbox, and then click Allow.
Step 11: Perform a Selective Startup (advanced users)
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:
How to perform a Selective startup
- In Control Panel, click System and Security, click Administrative Tools, and then double-click System Configuration.
Note If you are prompted for an administrator password or for confirmation, type the password or provide confirmation.
- Click the General tab, click Selective startup, and then clear the Load system services and the Load startup items check boxes.
- Select the Load system services check box, click OK, and then click Restart.
- If the problem reoccurs after you restart the computer, do one or both of the following tasks, as necessary.
To determine which system service is causing the problem
- In System Configuration, click the Services tab, click Disable all, select the check box for the first service that is listed, and then restart the computer.
Note If the problem doesn't reoccur, then you can eliminate the first service as the cause of the problem.
- With the first service selected, select the second service check box, and then restart the computer.
- Repeat this process until you reproduce the problem.
Note If you can't reproduce the problem, you can eliminate system services as the cause of the problem.
To determine which startup item is causing the problem
- In System Configuration, click the General tab, and then select the Load startup items check box.
- Click the Startup tab, click Disable all, select the check box for the first startup item that is listed, and then restart the computer.
Note If the problem doesn't reoccur, you can eliminate the first startup item as the cause of the problem.
- While the first startup item is selected, select the second startup item check box, and then restart the computer. Repeat this process until you reproduce the problem.
Step 12: Create a Windows user profile (advanced users)
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.
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.