Outlook Not Responding in Windows? Try These Fixes

Common causes

• Missing Windows or Office updates
• Outlook busy with another process, such as a large move or AutoArchive
• External content loading, such as images in an email
• An add-in that interferes with Outlook
• Very large mailboxes or folders
• An Office installation that needs repair
• Corrupted or damaged Outlook data files
• Antivirus software that is outdated or conflicts with Outlook

Step-by-Step Solutions

Find out which Outlook you use first, then work through the steps for it in order, from the quickest to the most time-consuming.

1. 1

   Step 1: Check which Outlook you’re using

   New Outlook and classic Outlook have different fixes, so start by finding out which one you have.

   New Outlook for Windows shows a toggle at the top right of its window. Classic Outlook is listed as Outlook (classic) in the Start menu app list.

   Microsoft’s classic Outlook steps don’t apply to new Outlook. If you use new Outlook, follow the next step. The steps after it are for classic Outlook.

   Good to know

   You may not see the toggle if classic Outlook isn’t installed on your PC.

2. 2

   Step 2: Restart or reinstall new Outlook

   For new Outlook, Microsoft’s steps are to close it in Task Manager and, if it keeps freezing, reinstall it.

   Right-click Start and select Task Manager. Select Microsoft Outlook, then End task. Check that new Outlook is closed, close Task Manager, then reopen Outlook as you normally would.

   If it still stops responding, uninstall it. From the Start menu, select new Outlook for Windows, select the arrow to expand the list option, then select Uninstall.

   To reinstall it, open the Microsoft Store app and select Get for new Outlook. If your accounts aren’t added automatically, follow the prompts to add your account.

   Good to know

   The Classic Outlook Advanced Diagnostics troubleshooter doesn’t work in new Outlook.

3. 3

   Step 3: Look for an open dialog box or a long task

   In classic Outlook, a dialog box waiting for an answer or a big job in progress can make Outlook look frozen.

   If a dialog box is waiting for you to choose an option, Outlook won’t let you do anything else. Press Alt+Tab to switch from window to window and find a dialog box that might be stopping Outlook from responding.

   If you just deleted or moved a large number of messages, Outlook can appear to freeze while it works behind the scenes. Check the status bar at the bottom of the screen and give Outlook a few minutes to finish.

   AutoArchive and syncing Outlook with a mobile device can also slow it down. If Outlook is busy, let the task finish before you try something else.

4. 4

   Step 4: Start classic Outlook in safe mode

   Office Safe Mode starts Outlook without add-ins, and it can also clear a screen stuck on Processing.

   Close Outlook. Right-click the Start button and click Run, or press the Windows logo key and the R key. Type outlook /safe and click OK.

   You can also press and hold the CTRL key while you double-click the Outlook shortcut, then click Yes when asked whether you want to start it in Safe Mode.

   If Outlook was stuck on a screen that says Processing, close it again and then open it normally. To leave Office Safe Mode at any time, exit and restart Outlook.

   Good to know

   Office Safe Mode is different from Windows safe mode.

5. 5

   Step 5: Turn off add-ins in classic Outlook

   Add-ins can interfere or conflict with Outlook, so turn them all off and then add them back one at a time.

   If the problem doesn’t happen in safe mode, select Options on the File menu, then select Add-Ins. Select COM Add-ins, then select Go. Clear all the check boxes in the list, select OK, and restart Outlook.

   If the problem doesn’t come back, one of the add-ins is likely the cause. Turn the add-ins back on one at a time until the problem returns, so you know which one is causing it.

6. 6

   Step 6: Stop automatic downloads of pictures

   Classic Outlook can freeze while it loads external content, such as images in an email message.

   Go to File, then Options, then Trust Center, then Automatic Download, and select both of these options:

   • Don’t download pictures or other content automatically in HTML e-mail
   • Warn me before downloading content when editing, forwarding, or replying e-mail
7. 7

   Step 7: Install Office and Windows updates

   Updates can correct problems by replacing out-of-date files.

   In classic Outlook, go to File, then Office Account. In the Product Information section, choose Update Options, then Update Now. If you don’t see Update Now, click Enable Updates first.

   You can also check from another Microsoft 365 app, such as Word: create a new document, then go to File, then Account.

   Microsoft also recommends setting Windows Update to automatically download and install recommended updates.

   Good to know

   If Update Options is missing and there’s only an About button, your company may be managing Office updates. Try Microsoft Update or contact your company help desk.

8. 8

   Step 8: Repair Office

   Repairing your Office programs can resolve classic Outlook not responding or freezing.

   Quit any Microsoft 365 programs that are running. In Control Panel, choose Programs and Features. In the list of installed programs, right-click your Microsoft 365 or Office product, then choose Change.

   For a Click-to-run installation, the most common type, select Online Repair, then Repair, in the window How would you like to repair your Office Programs. Quick Repair is faster, but it only detects and replaces corrupted files. For an MSI-based installation, select Repair in Change your installation, then click Continue.

   This repairs the entire Office suite, not just Outlook. You might need to restart your computer when it’s done.

9. 9

   Step 9: Repair your Outlook data file

   The Inbox Repair tool checks your classic Outlook data file for errors and repairs them.

   Back up your Outlook data file before you start the Inbox Repair tool (SCANPST.EXE). To see where your data files are, select File, then Account Settings, then Account Settings, and open the Data Files tab.

   Exit Outlook and open SCANPST.EXE. Select Browse to choose the Outlook Data File (.pst) you want to scan, then choose Start. If the scan finds errors, choose Repair.

   When the repair is complete, start Outlook with the profile that uses the file you just repaired. You may need to run the tool several times.

   Good to know

   For Outlook 2019 and Outlook 2016, Microsoft gives the tool’s location as C:\Program Files (x86)\Microsoft Office\root\Office16. The scan also creates a backup file during the repair.

10. 10

    Step 10: Create a new Outlook profile

    In classic Outlook, your profile stores settings that control how Outlook looks and feels, and you can create a new one.

    Close Outlook. In Control Panel, open Mail, then choose Show Profiles. Choose Add, type a name in the Profile Name box, and choose OK.

    Enter the email address and password of the main email account you use in Outlook, then follow the steps to create the profile. Add your other email accounts to the new profile too.

    On the Show Profiles dialog, choose Prompt for a profile to be used. Start Outlook and choose your new profile. If the new profile solves the problem, you can go back to Show Profiles and delete the old one.

Frequently Asked Questions