Your windows take a beating both from the indoors with dust and dirt as well as from the outdoors with different harsh weather conditions. On an annual basis, it is a good practice to clean those windows both from the inside and out and along with the window sills and screens. Depending on the size of your home, access to all the outside windows can difficult, and dangerous if long ladders are required. Many people do this themselves, but there are also professional window cleaners that you can hire to do the work for you.
The tools required for this job include a scraper, a scrubbing sponge and squeegee attachment, an extension pole, a bucket of water and window cleaning detergent, multiple smaller hand squeegee’s, and some microfiber towels.
The first thing to do is to remove all the outdoor screens and gently hose those off. Then make your water and soap solution in the bucket. Use the sponge to scrub down the window, and then use the squeegee to dry the window. If there are tough stains on the window, you might need to use a scraper to get them off.
Use the extension pole to reach windows that are high up and a microfiber cloth to wipe down the frames of any excess water. Here is a video from iScaper on how to clean your windows.