tl;dr
As Lee_Dailey notes, you must use pwsh.exe, not powershell.exe, to start a version of PowerShell [Core] v6+ and you must invoke the desired version's specific executable.
In the simplest case:
pwsh -Command "XXXXX"
Note that I've replaced {XXXXX} with "XXXXX", because you cannot directly execute script blocks ({...}) from outside PowerShell - just supply the commands as a string.
Given that - unlike with Windows PowerShell - you can install multiple PowerShell [Core] versions side by side:
Run pwsh -version (sic; see below) to report the version in your system's path (the instance that comes first among the directories listed in the PATH environment variable, $env:PATH).
If it is not the one you want to target, you'll have to invoke it via its full path:
If you want to rely on the standard installation location, you can use the following on Windows for version 7.0: "C:\Program Files\PowerShell\7\pwsh.exe"
To determine the target version's executable location reliably, open an interactive console for it and run (Get-Process -Id $PID).Path
The -Version parameter of powershell.exe, the Windows PowerShell CLI, does not allow you to start just any PowerShell version, only an older version of Windows PowerShell:
- In fact, the only supported argument is
-Version 2, and even that will only succeed if you have previously installed the required legacy versions of .NET Framework.
- Caveat: While versions higher than v5.1 - the latest and last Windows PowerShell version - sensibly result in an error (the one you saw), unsupported lower versions are quietly ignored; in effect,
-Version 1 and -Version 2 will both start version 2.0, whereas -Version 3, -Version 4 and -Version 5 are effectively ignored and run v5.1 - verify with $PSVersionTable.PSVersion
While a -Version parameter still exists in pwsh.exe, the PowerShell [Core] v6+ CLI, its meaning has changed:
It now simply reports a version number, namely the targeted executable's own (and therefore takes no argument).
powershell.exe... it ispwsh.exe... [grin]