If the start menu stops opening or you cannot use icons from the taskbar, you can reinstall the Windows taskbar:
Press Windows Key+X > Click Powershell (Admin) > Copy the below and paste into Powershell > Enter > Reboot your computer
Get-AppXPackage -Name Microsoft.Windows.ShellExperienceHost | Foreach {Add-AppxPackage -DisableDevelopmentMode -Register "$($_.InstallLocation)\AppXManifest.xml"}
To restart the explorer:
Press CTRL+SHIFT+ESC > Locate Windows Explorer in Processes tab and kill it > File > Run new task > Enter “explorer.exe” and Enter