Use the System File Checker tool to repair missing or corrupted system ...
When critical Windows system files are missing or corrupted, some Windows features may stop working correctly or Windows may stop responding altogether. If this happens, you can use the Deployment Image Servicing and Management tool (DISM) and the System File Checker tool (SFC) to scan your system files and restore any corrupted or missing files.
Gaming Services Repair Tool for PC | Xbox Support
If you are having issues installing or updating Gaming Services on your PC, or if you are noticing that the Xbox app for PC is launching with missing content, you may want to download and run the Gaming Services Repair Tool for PC.
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.
Windows troubleshooters - Microsoft Support
Get Help has troubleshooters you can run for many common scenarios. These often help resolve issues without the need to contact support. If a troubleshooter is available for your issue, select Run to start that troubleshooter.
How to troubleshoot Windows Installer errors - Microsoft Support
When you install, uninstall, or update a program on a Windows-based computer, you may receive one of the following error messages. The Windows Installer Service could not be accessed. Windows Installer Service couldn't be started. Could not start the Windows Installer service on Local Computer. Error 5: Access is denied.
Update for Visual C++ 2013 and Visual C++ Redistributable Package
When you use Microsoft Visual C++ 2013, you may encounter the following issues: Heap corruption occurs because of a synchronization bug in SetLocale, and this triggers an access violation. When you install an updated redistributable package, binaries for non-target architectures are removed.
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 start a scan for viruses or malware in Microsoft Defender
For the most complete scan, run Microsoft Defender Offline. For more about that see Help protect my PC with Microsoft Defender Offline. When the scan completes, Defender will tell you if it found anything. When would I want to run a scan?
Applies To: Microsoft Defender on Android, Microsoft Defender on Mac, Microsoft Defender on Windows
Microsoft 365 troubleshooters - Microsoft Support
Get Help has troubleshooters for Microsoft 365 you can run for many common scenarios. These often help resolve issues without the need to contact support. If a troubleshooter is available for your issue, select Start to run that troubleshooter. Use the Excel check troubleshooter to resolve Excel for Windows startup, hang, or crash issues.
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.