Turn Windows Security on or off. When you get a new device and start up Windows 10 for the first time, the antivirus protection that comes installed with the device is your default security app. However, Windows Security is pre-installed and ready for you to use at any time.

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.

Run an advanced scan in Windows Security. Select Start > Settings > Update & Security > Windows Security and then Virus & threat protection.

This update provides latest updates for Windows Security platform, which is comprised of the Windows Security app and its underlying service. To obtain the current version of Windows Security app, please run powershell command below: Get-AppPackage Microsoft.SecHealthUI.

If some Windows functions aren't working or Windows crashes, use the System File Checker to scan Windows and restore your files. Though the steps below might look complicated at first glance, just follow them in order, step-by-step, and we’ll try to get you back on track. Run the System File Checker tool (SFC.exe)

Protect your Android, iPhone, Mac, and Windows devices from threats by installing Microsoft Defender. Download Microsoft Defender on your devices either by: Scanning the following QR code. Searching for Microsoft Defender in your app store. Sharing with your devices, the following link: Copy link.

The Microsoft Defender Offline scan will automatically detect and remove or quarantine malware. Learn how to remove malware from your PC. Use Microsoft Defender Antivirus in Windows 10 or Windows 11 to scan your PC for malware, viruses, or other threats.

You can start a scan for malware any time you like. Note: Microsoft Defender currently offers anti-malware on Windows, Android, and macOS. From the Microsoft Defender dashboard. If you want a deeper scan, instead of selecting Quick scan in step 3, select Scan options and choose the type of scan you want.

Virus & threat protection in Windows Security helps you scan for threats on your device. You can also run different types of scans, see the results of your previous virus and threat scans, and get the latest protection offered by Microsoft Defender Antivirus. Under Current threats you can:

The Program Install and Uninstall troubleshooter helps you automatically repair issues when you're blocked from installing or removing programs.