Option Explicit 
Option Private Module 
 
Public hwndMain As Long 
 
Private Declare Function FindWindow Lib "user32.dll" Alias "FindWindowA" _ 
    (ByVal lpClassName As String, ByVal lpWindowName As String) As Long 
Private Declare Function SetWindowLong Lib "user32.dll" Alias "SetWindowLongA" _ 
    (ByVal hWnd As Long, ByVal nIndex As Long, ByVal WindowStyles As Long) As Long 
Private Declare Function ShowWindow Lib "user32.dll" _ 
    (ByVal hWnd As Long, ByVal nCmdShow As Long) As Long 
Enum WindowStyles 
    WS_OVERLAPPED = &H0 
    WS_POPUP = &H80000000 
    WS_CHILD = &H40000000 
    WS_MINIMIZE = &H20000000 
    WS_VISIBLE = &H10000000 
    WS_DISABLED = &H8000000 
    WS_CLIPSIBLINGS = &H4000000 
    WS_CLIPCHILDREN = &H2000000 
    WS_MAXIMIZE = &H1000000 
    WS_BORDER = &H800000 
    WS_DLGFRAME = &H400000 
    WS_VSCROLL = &H200000 
    WS_HSCROLL = &H100000 
    WS_SYSMENU = &H80000 
    WS_THICKFRAME = &H40000 
    WS_GROUP = &H20000 
    WS_TABSTOP = &H10000 
    WS_MINIMIZEBOX = &H20000 
    WS_MAXIMIZEBOX = &H10000 
    WS_CAPTION = WS_BORDER Or WS_DLGFRAME 
    WS_TILED = WS_OVERLAPPED 
    WS_ICONIC = WS_MINIMIZE 
    WS_SIZEBOX = WS_THICKFRAME 
    WS_OVERLAPPEDWINDOW = WS_OVERLAPPED Or WS_CAPTION Or WS_SYSMENU Or WS_THICKFRAME Or WS_MINIMIZEBOX Or WS_MAXIMIZEBOX 
    WS_TILEDWINDOW = WS_OVERLAPPEDWINDOW 
    WS_POPUPWINDOW = WS_POPUP Or WS_BORDER Or WS_SYSMENU 
    WS_CHILDWINDOW = WS_CHILD 
End Enum 
 
Public Sub FormStart(fForm As MSForms.UserForm, bMax As Boolean) 
Application.EnableCancelKey = xlDisabled 
hwndMain = FindWindow("ThunderDFrame", fForm.Caption) 
Do While hwndMain = 0 
    hwndMain = FindWindow("ThunderDFrame", fForm.Caption) 
    DoEvents 
Loop 
If bMax = True Then 
    SetWindowLong hwndMain, -16, WS_CAPTION + WS_SYSMENU + WS_MINIMIZEBOX + WS_MAXIMIZEBOX '+ WS_SIZEBOX 
    Else 
    SetWindowLong hwndMain, -16, WS_CAPTION + WS_SYSMENU + WS_MINIMIZEBOX '+ WS_MAXIMIZEBOX '+ WS_SIZEBOX 
End If 
DoEvents 
ShowWindow hwndMain, 1 
End Sub