Use the System File Checker tool to repair missing or corrupted system ...
The sfc /scannow command will scan all protected system files, and replace corrupted files with a cached copy that is located in a compressed folder at %WinDir% \System32\dllcache. The %WinDir% placeholder represents the Windows operating system folder. For example, C:\Windows.
How to start a scan for viruses or malware in Microsoft Defender
Learn how to protect yourself and how Microsoft Defender is helping to prevent fraud. See: National Public Data breach: What you need to know. 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.
Applies To:
Microsoft Defender on Android, Microsoft Defender on Mac, Microsoft Defender on Windows
Uninstall or remove apps and programs in Windows - Microsoft Support
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. You can try to repair a program first, if it's just not running correctly.
Remove malware from your Windows PC - Microsoft Support
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.
Applies To:
OneDrive (home or personal), OneDrive for 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. In the File Download dialog box, click Run or Open, and then follow the steps in the Windows Security Troubleshooter.
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
Block you from uninstalling a program through Add or Remove Programs (or Programs and Features) in Control Panel. If you're trying to remove malware, you can use Windows Security (or another antivirus tool), or you can use the Windows Malicious Software Removal tool.
How to use the PC Health Check app - Microsoft Support
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.
Installing Microsoft Defender - Microsoft Support
Microsoft Defender scans apps and files on your device to watch for possible threats. To do that, it needs to be able to access those files. We only use that permission to look for malicious apps, a process that happens entirely on your device. No information about your apps or files is sent to Microsoft. Send notifications.
Applies To:
Microsoft Defender on Android, Microsoft Defender on iOS, Microsoft Defender on Mac, Microsoft Defender on Windows
Codecs in Media Player - Microsoft Support
Windows includes codecs that allow Media Player to play the following formats out of the box: Codec packs add additional codec support to Windows. Apps like Media Player will then be able to play media files encoded in these formats. The following codecs packs are available: Adds support for the MPEG-1 and MPEG-2 video formats.