The answer to 'how to clean window' is to use a combination of a microfiber cloth, window cleaner, and a squeegee. First, wipe down the window with a microfiber cloth to remove any loose dirt or debris. Then, spray the window cleaner directly onto the glass and use the squeegee to wipe it clean, starting at the top and working your way down in overlapping strokes. Be sure to dry the edges with a clean microfiber cloth to prevent water spots.
For best results, clean your windows on an overcast day or in the shade to prevent the cleaner from drying too quickly. You may need to do several passes with the squeegee to get a streak-free finish. If you have hard water stains or other stubborn buildup, you may need to use a more specialized window cleaning solution or consider calling a professional window cleaning service.