How to Tell Which Version of PowerShell is Installed

One of the easiest ways I've found to determine which version of PowerShell is installed on a computer is to run the $host.version command.

The output will display the Major version, Minor version, Build, and Revision number. For example, here is the output from a computer with PowerShell V1 installed:



And here is the output from a Windows Server 2008 R2 beta computer, which has PowerShell V2 integrated into the operating system:

Note that the Build and Revision numbers are -1, indicating that the PowerShell V2 CTP (beta) is installed. Once PowerShell V2 RTW (Release to Web) is available, the Build and Revision numbers should both be zero.