Add this value to the registry via Powershell in order to add a right-click "Run as administrator" powershell context
New-Item -Path "Registry::HKEY_CLASSES_ROOT\Microsoft.PowershellScript.1\Shell\runas\command" ` -Force -Name '' -Value '"c:\windows\system32\windowspowershell\v1.0\powershell.exe" -noexit "%1"'
https://www.microsoft.com/en-us/download/details.aspx?id=41950