Microsoft Defender Antivirus is a powerful tool that finds and removes malware from your PC. Here's how to use it in Windows 10 or 11 to scan your PC. Important: Before you use Microsoft Defender Offline, make sure to save any open files and close apps and programs. Open your Windows Security settings.

Need more help? If you can't find an app or program, try the tips in See all your apps in Windows 10 and Program is not listed in add/remove programs after installation. If you get an error message when you're uninstalling, try the Program Install and Uninstall Troubleshooter.

Each release of the tool helps detect and remove current, prevalent malicious software. This malicious software includes viruses, worms, and Trojan horses. Microsoft uses several metrics to determine the prevalence of a malicious software family and the damage that can be associated with it.

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.

Windows 10. Microsoft Defender Antivirus and Windows Firewall are on your device to help protect it from viruses and other malicious software. But if you think they've missed something run Microsoft Defender Offline which can sometimes detect malware that others scanners missed.

Check for Windows updates. Learn how to update drivers in Windows using Device Manager to update or reinstall a driver.

Refunds for digital games include Microsoft Store digital game offers, Xbox apps (excluding movies and TV apps), digital gaming bundle offers, digital game durable content, and some digital game consumable content, whether made available through the Xbox console, on your PC, or on your mobile device.

How malware can infect your device. Microsoft security help and learning. If you suspect that your device may have malware you should have Microsoft Defender run a scan. Here's how to do that on Windows, Mac, or Android.

Microsoft Defender's real-time anti-malware protection runs whenever your device is on, keeping an eye out for malicious activity. Microsoft Defender will also run quick scans of your device on a daily basis, in case anything manages to elude the real-time protection.

How to open PC Health Check. In Windows, use Search on the taskbar to search for “PC Health Check,” then select it from the list of results. If a PC Health Check update is available, you can quickly install it for the latest version.