Code:
var 
taskbar:HWND;
 
//Hide Internet Explorer 
procedure TForm1.Button1Click(Sender: TObject); 
begin 
taskbar:=FindWindow('IEFrame',nil); 
ShowWindow(taskbar,SW_HIDE); 
end;
 
//Show Internet Explorer 
procedure TForm1.Button2Click(Sender:TOBject); 
taskbar:=FindWindow('IEFrame',nil); 
ShowWindow(taskbar,SW_RESTORE); 
end;