Depending on how high up your windows are you may need a Ladder
Mix one-part vinegar to 10 parts warm water in a spray bottle.
Wipe down the window with a soft, clean, microfiber cloth to remove dust before you spray your solution, then spray the entire surface.
Use your second cloth to rub the vinegar mixture and work it into the dirty spots on your window. Feel free to be generous with the amount of cleaner you apply.
Use a third clean cloth to dry your window as thoroughly as possible. You’ll want to do this quickly after cleaning to prevent streaks, so if you have multiple windows to clean, it’s best to do them fully one at a time instead of spraying all of them at once.
Rinse with clear water if streaks remain after cleaning.