How to truly disable Cortana

The answer from https://www.pcworld.com/article/2949759/windows/killing-cortana-how-to-disable-windows-10s-info-hungry-digital-assistant.html doesn't work, because I've already set the AllowCortanas Value Data to '0':

The answer from Can I completely disable Cortana on Windows 10? doesn't work either:

PS C:\WINDOWS\system32> Remove-AppxPackage Microsoft.Windows.Cortana_1.9.6.16299_neutral_neutral_cw5n1h2txyewy
Remove-AppxPackage : Deployment failed with HRESULT: 0x80073CFA, Removal failed. Please contact your software vendor.
(Exception from HRESULT: 0x80073CFA)
error 0x80070032: AppX Deployment Remove operation on package
Microsoft.Windows.Cortana_1.9.6.16299_neutral_neutral_cw5n1h2txyewy from:
C:\Windows\SystemApps\Microsoft.Windows.Cortana_cw5n1h2txyewy failed. **This app is part of Windows and cannot be
uninstalled on a per-user basis**. An administrator can attempt to remove the app from the computer using Turn Windows
Features on or off. However, it may not be possible to uninstall the app.
NOTE: For additional information, look for [ActivityId] d9d3a5d3-e312-0001-fcc4-d3d912e3d301 in the Event Log or use
the command line Get-AppxLog -ActivityID d9d3a5d3-e312-0001-fcc4-d3d912e3d301
At line:1 char:1
+ Remove-AppxPackage Microsoft.Windows.Cortana_1.9.6.16299_neutral_neut ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : WriteError: (Microsoft.Windo...l_cw5n1h2txyewy:String) [Remove-AppxPackage], IOException
    + FullyQualifiedErrorId : DeploymentError,Microsoft.Windows.Appx.PackageManager.Commands.RemoveAppxPackageCommand

I've also seen a post that fiddle with group policies, I've done that as well. However it didn't work either.

So now, having rebooted my PC, I still see Cortana in my task:

UPDATE:

THIS IS NOT A DUPLICATE of the suggested.

• the first method has a "Warning about Taskbar Breakage"
• the second method will apparently "stopped working at some point"
• the Original method, Remove Cortana via Powershell RemoveAppPackage, is the one that I tried and didn't work.

The easiest way to disable certain privacy aspects of Cortana is to use a third-party tool such as O&O Software's free ShutUp10.

Part of Cortana, though, is Windows Search, so there would still be an occasional Cortana process such as file indexing. However, there should no longer be any use of the internet by Cortana.

You can remove Cortana completely, if you wish, but that also removes Windows Search (though that might not be an issue if you use a third-party tool such as DocFetcher or Mythicsoft's Agent Ransack, which provide increased search functionality). That said, after a Windows 10 update, expect that Cortana would be reinstalled. Apparently, the only way now to permanently avoid Cortana is to use another OS, such as Linux.