Enumerate COM Ports using VB.net

    Public Function foo() As Integer
    Try
        Dim searcher As New ManagementObjectSearcher( _
            "rootCIMV2", _
            "SELECT * FROM Win32_SerialPort")

        For Each queryObj As ManagementObject In searcher.Get()
            Debug.WriteLine(queryObj("Caption"))
            Debug.WriteLine(queryObj("Description"))
            Debug.WriteLine(queryObj("DeviceID"))
            Debug.WriteLine(queryObj("Name"))
            Debug.WriteLine(queryObj("PNPDeviceID"))

        Next
    Catch err As ManagementException
        Stop
    End Try
End Function

Public Function bar() As Integer
    Try
        Dim searcher As New ManagementObjectSearcher( _
            "rootCIMV2", _
            "SELECT * FROM Win32_PnPEntity WHERE ConfigManagerErrorCode = 0")

        For Each queryObj As ManagementObject In searcher.Get()
            If queryObj("Caption").ToString.Contains("(COM") Then
                Debug.WriteLine(queryObj("Caption"))
                Debug.WriteLine(queryObj("Description"))
                Debug.WriteLine(queryObj("DeviceID"))
                Debug.WriteLine(queryObj("Name"))
                Debug.WriteLine(queryObj("PNPDeviceID"))
            End If
        Next
    Catch err As ManagementException
        Stop
    End Try
End Function

source: http://stackoverflow.com/questions/2937585/how-to-open-a-serial-port-by-friendly-name/2937588#2937588