I have written the following Win app in VB.NET 2003 . The class is simply
picture boxes that behave in a random order after they have been
instantiated and added to a form. When I create 15 or more instances of my
class, the whole program runs slowly in a way that I have to close the
program. I have tried to create a new thread for each class, but that throws
an exception , because a separated thread can't be added to a form from a
child class.

My code is this ( please tell me if there are better ways for doing it)
coplile with :

vbc [filename]
/r:system.dll,system.windows.forms.dll,system.drawing.dll,microsoft.visualbasic.dll
/t:winexe /main:form1

'----------------------------------- Start of CODE

Imports System.Math
imports Microsoft.VisualBasic
imports System.drawing
imports system.windows.forms

Public Class Form1
   Inherits System.Windows.Forms.Form

#Region " Windows Form Designer generated code "

   Public Sub New()
       MyBase.New()

       'This call is required by the Windows Form Designer.
       InitializeComponent()

       'Add any initialization after the InitializeComponent() call

   End Sub

   'Form overrides dispose to clean up the component list.
   Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
       If disposing Then
           If Not (components Is Nothing) Then
               components.Dispose()
           End If
       End If
       MyBase.Dispose(disposing)
   End Sub

   'Required by the Windows Form Designer
   Private components As System.ComponentModel.IContainer

   'NOTE: The following procedure is required by the Windows Form Designer
   'It can be modified using the Windows Form Designer.
   'Do not modify it using the code editor.
   <System.Diagnostics.DebuggerStepThrough()> Private Sub
InitializeComponent()
       '
       'Form1
       '
       Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
       Me.BackColor = System.Drawing.Color.White
       Me.ClientSize = New System.Drawing.Size(384, 266)
       Me.Name = "Form1"
       Me.Text = "Form1"

   End Sub

#End Region

   Private Sub Form1_Click(ByVal sender As Object, ByVal e As
System.EventArgs) Handles MyBase.Click
       CreateOBJ()
   End Sub

   Sub CreateOBJ()
       Dim myRec As Rec = New Rec(Me.CreateGraphics, Me)
   End Sub
End Class

'--------------------------------------------------- Class Rec

Public Class Rec

   Dim Gr As Graphics
   Dim X, Y As Integer
   Dim frm As Form
   WithEvents TIMER As New Timer
   Dim bmp As Bitmap
   Dim PB As PictureBox

     Public Sub New(ByVal g As Graphics, ByVal form As Form)
       X = Rnd() * 100
       Y = Rnd() * 200
       Gr = g
       Me.frm = form
       ini()
       justAddX = True
       justAddY = True
   End Sub

   ' We could use the graphics object here to draw on the form. But since
GDI+
   ' lacks the ideal performance, we use picture boxes and add them to the
   ' spacified form instead of using the drawing object:

   Sub ini()
       TIMER.Interval = Rnd() * 10 + 1
       TIMER.Enabled = True
       PB = New PictureBox
       With PB
           .BackColor = Color.FromArgb(Rnd() * 150, Rnd() * 200, Rnd() *
230)
           .Left = X
           .Top = Y
           .Height = 6
           .Width = 6
       End With
       frm.Controls.Add(PB)
   End Sub

   ' Use these two boolean to know when to add or substarct numbers
   ' the movement of this class object.
   Dim justAddX, justAddY As Boolean

   Private Sub TIMER_Tick(ByVal sender As Object, ByVal e As
System.EventArgs) Handles TIMER.Tick
       MoveMe()
   End Sub

   ' CuurentNum X , Y are the numbers added to the speed of X ,Y
   ' which creates a kind of change when the Rec hits the walls:

   Dim CurrentNumX As Integer = 1
   Dim CurrentNumY As Integer = 1

   Sub MoveMe()
       If X > (frm.Width - PB.Width) - 10 Then
           justAddX = False
           CurrentNumX = Rnd() * 50
       End If

       If Y > (frm.Height - PB.Height) - 30 Then
           justAddY = False
           CurrentNumY = Rnd() * 40
       End If

       If X < 0 Then
           justAddX = True
           CurrentNumX = Rnd() * 80
       End If

       If Y < 0 Then
           justAddY = True
           CurrentNumY = Rnd() * 30
       End If

       If justAddX Then
           X += CurrentNumX
       Else
           X -= CurrentNumX
       End If

       If justAddY Then
           Y += CurrentNumY
       Else
           Y -= CurrentNumY
       End If

       PB.Left = X
       PB.Top = Y
   End Sub

End Class

'------------------------------------------------------- End of
CODE------------