PowerShell cmdlet Test-NetConnection not available
The availability of many cmdlets is tied to the Windows version, not the PowerShell version. If you can't upgrade your Windows version you can't have Test-NetConnection.
You could use a commandline port scanner like nmap or scanline for port tests, or you could connect to the port(s) yourself:
function Test-Port($server, $port) { $client = New-Object Net.Sockets.TcpClient try { $client.Connect($server, $port) $true } catch { $false } finally { $client.Dispose() }}