Hi Joe. Windows won't let your change amd or delete any file in use. To keep MSN Messenger from starting up when Windows starts, OPEN MSN Messenger and under the MENUS at the top look for Options or Preferences. Look carefully in those for a box that says;"Start when Windows Starts" to that effect and UNCHECK the box. Hit OK and close MSN. Then RIGHT click the icon down by the clock and choose EXIT or CLOSE. It's gone till you need it!