PowerShellのバージョンを確認

$PSVersionTable

 PS C:\> $PSVersionTable
 
 Name                           Value
 ----                           -----
 PSVersion                      5.1.14393.187
 PSEdition                      Desktop
 PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0...}
 BuildVersion                   10.0.14393.187
 CLRVersion                     4.0.30319.42000
 WSManStackVersion              3.0
 PSRemotingProtocolVersion      2.3
 SerializationVersion           1.1.0.1

参考

https://docs.microsoft.com/ja-jp/powershell/scripting/install/installing-windows-powershell?view=powershell-6