Sub Main(ByVal args() As String)
    Dim machineName As String = ""
    Dim categories() As PerformanceCounterCategory

    ' Copy the machine name argument into the local variable.
    Try
        machineName = IIf(args(0) = ".", "", args(0))
    Catch ex As Exception
    End Try

    ' Generate a list of categories registered on the specified computer.
    Try
        If machineName.Length > 0 Then
            categories = _
                PerformanceCounterCategory.GetCategories(machineName)
        Else
            categories = PerformanceCounterCategory.GetCategories()
        End If
    Catch ex As Exception
        Console.WriteLine("Unable to get categories on " & _
            IIf(machineName.Length > 0, "computer ""{0}"":", _
            "this computer:"), machineName)
        Console.WriteLine(ex.Message)
        Return
    End Try

    Console.WriteLine("These categories are registered on " & _
        IIf(machineName.Length > 0, _
            "computer ""{0}"":", "this computer:"), machineName)

    ' Create and sort an array of category names.
    Dim categoryNames(categories.Length - 1) As String
    Dim objX As Integer
    For objX = 0 To categories.Length - 1
        Console.WriteLine("{0}, {1}", objX, categories(objX).CategoryName)
        categoryNames(objX) = categories(objX).CategoryName
    Next objX
    Array.Sort(categoryNames)

    For objX = 0 To categories.Length - 1
        Console.WriteLine("{0,4} - {1}", objX + 1, categoryNames(objX))
    Next objX
End Sub