Use the System File Checker tool to repair missing or corrupted system ...
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)
Using System File Checker in Windows - Microsoft Support
System File Checker is a utility in Windows that checks for problems with files on your computer. To run it, follow these steps: Make sure you've installed the latest updates for Windows, and then restart your machine. To find out more, read Update Windows.
Automatically fix Windows security issues - Microsoft Support
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.
Remove malware from your Windows PC - Microsoft Support
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.
Applies To: OneDrive (home or personal), OneDrive for Windows
Update drivers manually in Windows - Microsoft Support
Learn how to update drivers in Windows using Device Manager to update or reinstall a driver.
Fix problems that block programs from being installed or removed
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.
Use System Restore - Microsoft Support
Use System restore to make restore points when you install a new app, driver, or Windows update, and when you create a restore point manually. Restoring won’t affect your personal files, but it will remove apps, drivers, and updates installed after the restore point was made.
How to use the PC Health Check app - Microsoft Support
Windows 11. 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. How to open PC Health Check.
How to start a scan for viruses or malware in Microsoft Defender
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.
Applies To: Microsoft Defender on Android, Microsoft Defender on Mac, Microsoft Defender on Windows
Check your device performance and health in Windows Security
To help you keep your device secure, Windows Security monitors your device for security issues and provides a health report, which appears on the Device performance & health page. The Health report alerts you to common issues in four key areas and offers recommendations to remedy them.