How and when should I clean the projection window?

• Clean the projection window whenever you notice dirt or dust on the surface.
  
  To remove dirt or smears on the window, use a commercially available cloth for cleaning glasses.
  
  Caution:
  • Do not rub the projection window with harsh materials or subject it to shocks, or you may damage the window.
  • Do not use wax, alcohol, benzene, paint thinner, or other chemical detergents. These can damage the case.
  
  Warning:
  Before you clean any part of the projector, turn it off and unplug the power cord. Never open any cover on the projector, except the lamp cover. Dangerous electrical voltages in the projector can injure you severely. Do not try to service this product yourself, except as specifically explained in the User's Guide. Refer all other servicing to qualified service personnel.