Applies ToWindows 10

Support for Windows 10 will end in October 2025

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: The Microsoft Support Diagnostic Tool (MSDT) is deprecated and will be removed from future versions of Windows. For more information, see Deprecation of Microsoft Support Diagnostic Tool (MSDT) and MSDT Troubleshooters.

Follow these steps to automatically diagnose and repair Windows security problems by turning on UAC, DEP protection, Windows Firewall, and other Windows security options and features.

  • Select the Download button on this page.

  • In the File Download dialog box, click Run or Open, and then follow the steps in the Windows Security Troubleshooter.

Notes: 

  • This troubleshooter might be in English only. However, the automatic fix also works for versions of Windows in other languages.

  • If you're not on the computer that has the problem, save the troubleshooter to a flash drive or a CD, and then run it on the computer that has the problem.

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What it fixes

  • Checks the following Windows security features and enables them if needed

  • Phishing Filter or Smartscreen Filter

  • User Account Control (UAC)

  • Data Execution Prevention (DEP)

  • Windows Firewall

  • Antivirus protection status and updates

See also

Stay protected with Windows Security

What's new in Windows Security

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