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.

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.

The Windows Malicious Software Removal Tool (MSRT) helps remove malicious software from computers that are running any of the following operating systems: Windows 11. Windows Server 2022. Windows 10. Windows Server 2019. Windows Server 2016. Windows 8.1. Windows Server 2012 R2. Windows Server 2008 R2. Windows 7. Windows Server 2008.

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.

Free up drive space in Windows. If your PC is running low on free space, you might not be able to install important Windows updates, and your PC’s performance may be affected. Here are some ways to free up space so you can keep your PC up to date and running smoothly.

The Program Install and Uninstall troubleshooter helps you automatically repair issues when you're blocked from installing or removing programs. It also fixes corrupted registry keys. First, you'll need to download the troubleshooter. Download troubleshooter.

Windows 11 Windows 10. When it comes to optimizing your Windows device, one of the key optimization areas is the startup process. The applications that run automatically when your device boots up can impact both the speed of your startup and the overall performance of your system.

Windows provides a variety of configuration tools tailored to meet the needs of different users. These built-in tools facilitate your device's customization and monitoring, allowing you to change Windows' configuration to suit your preferences and requirements with precision.

You can start a scan for malware any time you like. Note: Microsoft Defender currently offers anti-malware on Windows, Android, and macOS. 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.

You suspect your device has been infected. Use installation media to reinstall Windows 11. Select one of the recovery options below and follow the steps to try to get things working again. If you've recently installed a Windows update, uninstall the update to try to resolve the issue.