[_Setup]  
AppName=My Program  
AppVerName=My Program 1.5  
DefaultDirName={pf}\My Program  
   
[_Code]  
function GetSystemMenu(hWnd: HWND; bRevert: BOOL): LongWord; external 'GetSystemMenu@user32.dll stdcall';  
function DeleteMenu(hMenu: LongWord; uPosition, uFlags: UINT): BOOL; external 'DeleteMenu@user32.dll stdcall';  
   
procedure InitializeWizard();  
begin  
   DeleteMenu(GetSystemMenu(WizardForm.Handle,False),61536,0);  
end;