'Imports System.Runtime.InteropServices
Public Class Form1
 
    Private f As Form
 
    Public Const WS_EX_TOOLWINDOW As Int32 = &H80
    Public Const WS_EX_APPWINDOW As Int32 = &H40000
 
    Protected Overrides ReadOnly Property CreateParams() As CreateParams
        Get
            Dim cp As CreateParams = MyBase.CreateParams
            cp.ExStyle = (cp.ExStyle Or CType(WS_EX_TOOLWINDOW, Integer))
            cp.ExStyle = (cp.ExStyle - CType(WS_EX_APPWINDOW, Integer))
            Return cp
        End Get
    End Property
 
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles MyBase.Load
        Me.FormBorderStyle = Windows.Forms.FormBorderStyle.None
        f = New Form
        f.FormBorderStyle = Windows.Forms.FormBorderStyle.None
        f.Show()
    End Sub
End Class