Outlook for Windows not responding, hangs, freezes, or stops working

Restart new Outlook

1. Right-click Start and select Task Manager.

2. Select Microsoft Outlook, then End task.

3. Check to make sure that new Outlook is closed, then close Task Manager.

4. After new Outlook closes, reopen the app as you normally would.

Uninstall and reinstall new Outlook for Windows

Follow these steps to uninstall new Outlook for Windows:

1. From the Start menu, select new Outlook for Windows.

2. Select the arrow to expand the list option in Start.

3. Select Uninstall to begin the uninstall process.

To reinstall new Outlook for Windows, you'll need to get it from the Microsoft Store:

1. Open the Microsoft Store on Windows app.

   Get new Outlook

2. Select Get if you need to download new Outlook, or Open if it is already installed.

3. If your accounts aren't added automatically, follow the prompts to add your account and start using new Outlook.

Check for other processes running under classic Outlook for Windows

Occasionally, classic Outlook tries to run a process in the background. Auto-archive, sending and receiving a very large attachment, or running some of the other mailbox tools can all be done in the background. Check the status bar at the bottom of the screen to see if another process is running. If so, wait a short time (usually two or three minutes) to see if classic Outlook starts working again.

Check for Windows and Office for Windows updates

Check for Microsoft 365 or Office updates as well as Windows updates to install any important, recommended, and optional updates. These updates can often correct problems by replacing out-of-date files and fixing vulnerabilities.

To install the latest Windows updates, go to Install Windows Updates.

To install the latest Microsoft 365 or Office for Windows updates, go to How to update Microsoft 365 or Office for Windows.

Start classic Outlook for Windows in safe mode

Sometimes add-ins can conflict with classic Outlook for Windows. Starting Outlook in safe mode, which starts Outlook without add-ins loaded, can tell you if an add-in is the source of the problem.

1. Right-click the Start button in Windows, and click Run. Alternatively, you can press the Windows logo key and the R key on your keyboard.

2. In the Run box, type outlook.exe /safe, and click OK.

3. If a Choose Profile dialog box appears, accept the default setting and choose OK.

4. If prompted, enter your password and choose Accept.

If classic Outlook is able to start in safe mode, then the problem is likely with one of your add-ins. While in safe mode, you'll need to disable all of your COM add-ins before restarting Outlook:

1. In Outlook, open the File menu, select Options, and then select Add-ins.

2. Select COM Add-ins, and select Go.

   Tip: You may want to manually record the title of every selected add-in listed under Available Add-ins, or take a screenshot and save the image.

3. Clear all the check boxes in the list to disable the add-ins and select OK.

   Caution: Click a check box to clear it. Don't select an add-in and choose Remove. If you have administrator rights, you could actually delete the add-in. For this troubleshooting exercise, you want to disable, not delete, an add-in.

4. Restart Outlook.

5. If the issue does not occur, go back to the COM Add-ins screen and enable them one at a time until the error occurs (be sure to close and restart classic Outlook after each add-in is enabled). This will tell you which add-in is the source of the error. When this occurs you'll need to restart Outlook in safe mode again so that you can disable the add-in causing the problem.

Create a new profile in classic Outlook for Windows

Your profile contains your classic Outlook for Windows settings. Occasionally, that profile can become corrupted. You can determine if it's corrupted by creating a new profile and changing which profile is used when Outlook starts.

To create a new Outlook profile, go to Create an Outlook profile.

Once the new profile is created, close Outlook, and do the following:

1. Hold the Shift key while restarting Outlook.

2. In the Choose Profile dialog box, choose the new profile name you created from the drop-down list.

3. Choose OK.

If the Outlook problem is fixed using the new profile, you've identified your original Outlook profile as being corrupt and the source of your problem.

Repair your classic Outlook for Windows data files

Classic Outlook for Windows stores all your email messages, meetings and events, contacts, and tasks in data files. These files occasionally might become corrupted. You can run the Inbox Repair Tool (scanpst.exe) to scan your Outlook data files and repair errors.

For information on how to run the Inbox Repair Tool, go to Repair Outlook data files (.pst and .ost).

Repair Office for Windows

This step is useful if one of the Outlook files is damaged or corrupted. Try a quick repair first, and if that doesn't work, try the online repair.

For more information on how to repair Office, go to Repair an Office application.