<p>I thought that I had the latest CTP of PowerShell 2 but when I try the command:</p>

<p><code>invoke-expression –computername Server01 –command 'get-process PowerShell'</code></p>

<p>I get an error message:<br>
<strong>A parameter cannot be found that matches parameter name 'computername'.</strong></p>

<p>So the question is: How can I tell which version of PowerShell I have installed? And what the latest version is?</p>

```
$host.version.tostring()
```
will return the version number.
RTM of v1 is 1.0.0.0
Couldn't honestly tell you what the latest version of the previews are because I haven't had a chance to play yet.