Hiding the SysMenu

Yes, that will work, but it's just the same as disabling the the ControlBox property.

Just incase your interested, here's the code

Private Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA" (ByVal hwnd As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long
Private Declare Function GetWindowLong Lib "user32" Alias "GetWindowLongA" (ByVal hwnd As Long, ByVal nIndex As Long) As Long
Private Const GWL_STYLE = (-16)
Private Const WS_SYSMENU = &H80000

Private Sub Form_Load()
    Dim wStyle As Long
    wStyle = GetWindowLong(hwnd, GWL_STYLE)
    wStyle = wStyle Xor WS_SYSMENU
    SetWindowLong hwnd, GWL_STYLE, wStyle
End Sub