How to find the version of PowerShell

Two ways:

PS> $PSVersionTable

Name                           Value
----                           -----
PSVersion                      5.0.9879.0
WSManStackVersion              3.0
SerializationVersion           1.1.0.1
CLRVersion                     4.0.30319.0
BuildVersion                   6.4.9879.0
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0...}
PSRemotingProtocolVersion      2.2


PS> Get-Host


Name             : ConsoleHost
Version          : 5.0.9879.0
InstanceId       : 921cb62e-6fa2-4b7a-9821-3e28b90006c9
UI               : System.Management.Automation.Internal.Host.InternalHostUserInterface
CurrentCulture   : en-US
CurrentUICulture : en-US
PrivateData      : Microsoft.PowerShell.ConsoleHost+ConsoleColorProxy
IsRunspacePushed : False
Runspace         : System.Management.Automation.Runspaces.LocalRunspace

PS> $PSVersionTable

Name Value

---- -----

PSVersion 5.0.9879.0

WSManStackVersion 3.0

SerializationVersion 1.1.0.1

CLRVersion 4.0.30319.0

BuildVersion 6.4.9879.0

PSCompatibleVersions {1.0, 2.0, 3.0, 4.0...}

PSRemotingProtocolVersion 2.2

PS> Get-Host

Name : ConsoleHost

Version : 5.0.9879.0

InstanceId : 921cb62e-6fa2-4b7a-9821-3e28b90006c9

UI : System.Management.Automation.Internal.Host.InternalHostUserInterface

CurrentCulture : en-US

CurrentUICulture : en-US

PrivateData : Microsoft.PowerShell.ConsoleHost+ConsoleColorProxy

IsRunspacePushed : False

Runspace : System.Management.Automation.Runspaces.LocalRunspace

And if you want to check whether PowerShell is installed or not, check the Registry.