Private Declare Function GetSystemMenu Lib "user32" (ByVal hwnd As Long, ByVal bRevert As Long) As Long
Private Declare Function DeleteMenu Lib "user32" (ByVal hMenu As Long, ByVal nPosition As Long, ByVal wFlags As Long) As Long
Private Sub couic_Click()
Dim sysmen As Long
sysmen = GetSystemMenu(Me.hwnd, 0)
DeleteMenu sysmen, SC_MOVE, &H0&
End Sub
Et sous VB.Net ce devrait être la même chose en rempaçant Long par Integer ...