From: https://superuser.com/a/955711/65216
Reinstall Cortana using the following procedure:
-
Open an elevated Command Prompt window (press win + X, and then press A)
-
Type
start powershell
and press enter -
Run the command (in one line):
Get-AppXPackage -Name Microsoft.Windows.Cortana | Foreach {Add-AppxPackage -DisableDevelopmentMode -Register "$($_.InstallLocation)\AppXManifest.xml"}