Windows 10 critical error: Start menu and Cortana doesn’t work

In order to fix the “Start menu and Cortana” error you must do the following steps:

1. Open Task manager
2. Click on File > Run new task
3. Write PowerShell
4. Write this command on PowerShell prompt: “Get-AppXPackage-AllUsers|Foreach{Add-AppxPackage-DisableDevelopmentMode-register”$($_InstallLocation.)\AppXManifest.xml”}”
5. Close the PowerShell window and restart the computer.