Studying your screenshot it appears the registry error in your first post is resolved but the issue now is one that is a common problem with Start Menu usually solved by reinstalling these with Powershell:
"Microsoft.Windows.ShellExperienceHost and Microsoft.Windows.Cortana applications need to be installed correctly"
Try the fixes here:
https://answers.microsoft.com/en-us/windows/for...
https://appuals.com/microsoft-windows-shellexpe... (Avoid ad links which intrude into editorial copy, especially avoid Restoro and Reimage ads)
https://superuser.com/questions/1123371/windows...
https://superuser.com/questions/1602324/windows...
https://windowsreport.com/shell-experience-host... (Avoid ad links which intrude into editorial copy, especially avoid Restoro and Reimage ads)
https://www.winhelponline.com/blog/start-and-ta...
Keep me posted on your progress as I will be here to help until the case is resolved.