To get rid of mold on windows, a solution of bleach and household cleaners is the best option. It is important to use cleaners without ammonia, as it can react negatively with bleach.
To prepare the solution of bleach, mix one cup of bleach per one gallon of water, then pour the solution into a spray bottle. A mixture of an ammonia-free general household cleaner and water should be poured into a second spray bottle, and warm tap water should be placed into a third spray bottle. Safety equipment, such as goggles and rubber gloves, are important to wear during this preparation.
To remove the mold from windows, spray the visible mold with the general household cleaner solution, and wipe it away. Spray the area with clean water, and then wipe the water away, being sure to throw the towels away frequently. Allow the window and surrounding area to completely dry, usually around 15 minutes, and then apply the bleach. Wipe the bleach away, then spray the area with clean water a second time.
After the second application of water is dry, it is important to clean the area with a vacuum cleaner with a high-efficiency particulate arrestance filter. This helps to remove all of the mold fragments that may be around the window.