Fixes or workarounds for recent issues in classic Outlook for Windows.

Use the System File Checker tool to repair missing or corrupted system files. When critical Windows system files are missing or corrupted, some Windows features may stop working correctly or Windows may stop responding altogether.

To help you resolve this, try the solutions below. We've listed the most common solutions first so try the steps in the order they're listed. Make sure Office is updated to Version 2102 (Build 13801.20808) or later. If you're not setup for automatic updates do the following:

Troubleshoots and fixes common issues with security and malware prevention in Windows.

Learn how to resolve errors related to running Office installed by Click-to-Run and Windows Installer (MSI).

Here's how to do that on Windows, Mac, or Android.

First, you'll need to download the troubleshooter. Download troubleshooter. If you see the File Download box when you start downloading, select Run or Open. The troubleshooter provides steps for you to follow. If a program isn't listed in the uninstall options, you'll be asked for that program's product code.

When trying to start a Microsoft 365 app, you might get this error. Here are some things you can try to fix the problem. We've listed the most common solutions first, so try them in order. Wait a few minutes, restart your device, sign back in, and restart your app. How you get to the repair tool depends on your operating system.

Go to Control Panel in Microsoft Windows. Choose Uninstall a program. Find Microsoft Office on your program list and click on it. Choose Change from the toolbar at the top of the program list. In the dialog box that appears choose Quick Repair and then click the Repair button.

Right-click the Start button (lower-left corner) and select Apps and Features on the pop-up menu. Select the Microsoft 365 or Office product you want to repair and select Modify. Note: This will repair the entire Office suite even if it's just one application you want to repair such as Word or Excel.