Visually remove/disable close button from title bar .NET

Question

I have been asked to remove or disable the close button from our VB .NET 2005 MDI application. There are no native properties on a form that allow you to grey out the close

Answer 1

Prevent to close the form, but hide it:

Private Sub Form1_Closing(ByVal sender As System.Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles MyBase.Closing
    Me.WindowState = FormWindowState.Minimized 
    Me.Visible=false
    e.Cancel = True
End Sub