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.

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.

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.

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.

Uninstall or remove apps and programs in Windows. There are different ways to remove apps and programs, so if you can't find the one you're looking for, you can try another location. Note that some apps and programs are built into Windows and can't be uninstalled.

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.

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.

Windows Security is your home to manage the tools that protect your device and your data: Virus & threat protection - Monitor threats to your device, run scans, and get updates to help detect the latest threats. (Some of these options are unavailable if you're running Windows 10 in S mode.)

Take a snapshot to copy words or images from all or part of your PC screen. Use Snipping Tool to make changes or notes, then save, and share. Capture any of the following types of snips: Free-form snip. Draw a free-form shape around an object. Rectangular snip.

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.