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.

See how to help protect yourself from potentially unsafe active content, such as macros or ActiveX controls.

After October 14, 2025, Microsoft will no longer provide free software updates from Windows Update, technical assistance, or security fixes for Windows 10. Your PC will still work, but we recommend moving to Windows 11. Learn more. Note: Use these steps for Windows programs.

You'll always receive notifications when there's a problem that requires immediate action. The settings on this page simply let you specify whether you want to know things such as that a threat was successfully blocked, or that a malware scan completed uneventfully

Learn about the Windows Security app and some of the most common tools you can use.

Potentially unwanted applications (PUA) are a category of software that can cause your device to run slowly, display unexpected ads, or at worst, install other software which may be more harmful or annoying. PUA isn’t malware, but it is software that you often don’t need and probably don’t want.

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

Learn how to manage and configure notifications in Windows, including using the "Do Not Disturb" feature to silence alerts and stay focused. Discover how to activate "Do Not Disturb" from the Notification Center and use shortcuts to enhance productivity.

When Windows Security detects a potentially unwanted app you'll get a notification encouraging you to take action on it. Click on the notification to go to the Virus & threat protection area of Windows Security, then click on the name of the PUA to select the action to take.

The WinHlp32.exe technology will not be supported in its current form in future Windows releases. Therefore, we strongly recommend that software developers no longer use this Windows Help program.