Fix problems that block programs from being installed or removed
First, you'll need to download the troubleshooter. Download troubleshooter. If you see the File Download box when you start downloading, select Run or Open. The troubleshooter provides steps for you to follow. If a program isn't listed in the uninstall options, you'll be asked for that program's product code.
Description of the Windows Registry Checker Tool (Scanreg.exe)
When you start your computer successfully, the Windows Registry Checker tool (Scanreg.exe) creates a backup of system files and registry configuration information (including user account information, protocol bindings, software program settings, and user preferences) once daily.
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.
Fix problems that block programs from being installed or removed
First, you'll need to download the troubleshooter. Download troubleshooter. If you see the File Download box when you start downloading, select Run or Open. The troubleshooter provides steps for you to follow. If a program isn't listed in the uninstall options, you'll be asked for that program's product code.
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.
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. Notes:
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. Select the type of scan you want to run, then Start scan. 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
Removing Invalid Entries in the Add/Remove Programs Tool
Start Registry Editor (Regedit.exe). Locate the key to be deleted by locating the key name created by the program. If the name of the key is not apparent, browse through each key and note the value for DisplayName. This is the viewable string in the Add/Remove Programs tool.
How to use the Regsvr32 tool and troubleshoot Regsvr32 error messages
Regsvr32 is a command-line utility to register and unregister OLE controls, such as DLLs and ActiveX controls in the Windows Registry. Regsvr32.exe is installed in the %systemroot%\System32 folder in Windows XP and later versions of Windows. The 64-bit version is %systemroot%\System32\regsvr32.exe.
How to back up and restore the registry in Windows - Microsoft Support
Select Start , type regedit.exe in the search box, and then press Enter. If you are prompted for an administrator password or for confirmation, type the password or provide confirmation. In Registry Editor, locate and click the registry key or subkey that you want to back up. Select File > Export.