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.

PC Health Check app brings you up to date info on your Windows device health, helping you take action to improve your device performance and troubleshoot performance problems. It is periodically updated based on customer feedback to help you make the most of your Windows PC.

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.

Learn how to run Windows Update Troubleshooter to resolve errors downloading or installing Windows updates.

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.