Windows PowerShell 2.0 needs to be installed on Windows Server 2008 and Windows Vista only. It is already installed on Windows Server 2008 R2 and Windows 7.
However, powershell.exe lives here %SystemRoot%\system32\WindowsPowerShell\v1.0\powershell.exe. That doesn't seem like it would be PowerShell 2.0. The file version of powershell.exe is 6.1.7600.16385 so that doesn't help much either.
How do I know for sure if I have Window PowerShell 2.0 installed and if I don't, where is a download link for Windows 7?