Option Explicit
Const WS_BORDER = &H800000
Const WS_THICKFRAME = &H40000
Const WS_CAPTION = &HC00000
Const WS_MAXIMIZEBOX As Long = &H10000
Const WS_MINIMIZEBOX As Long = &H20000

Private Const GWL_STYLE = (-16)

Private Declare Function GetWindowLong Lib "user32" Alias "GetWindowLongA" (ByVal hwnd As Long, ByVal nIndex As Long) As Long
Private Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA" (ByVal hwnd As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long

Private Sub Form_Load()
SetWindowLong Me.hwnd, GWL_STYLE, GetWindowLong(Me.hwnd, GWL_STYLE) And Not WS_MAXIMIZEBOX And Not WS_MINIMIZEBOX And Not WS_THICKFRAME And Not WS_CAPTION
End Sub