Mix a solution of one-part white vinegar to three parts water in a bucket.
Wet your window washing tool (a sponge, squeegee, or brush) with the vinegar mixture and scrub the window from top to bottom.
Rinse the window with clean water and a squeegee or wipe the excess water with a cloth or towel.
Dip your window washing tool in the vinegar mixture and scrub any spots or streaks on the window.
Rinse the window thoroughly with clean water and a squeegee or wipe the excess water with a cloth or towel.