The answer to 'window mildew' is that mildew is a type of fungus that can grow on windows, especially in damp or humid environments. Symptoms of window mildew include a white, powdery substance on the glass or window frame, as well as a musty odor. Common causes of window mildew include poor ventilation, high humidity, and condensation buildup.
To address window mildew, you can try DIY cleaning solutions like vinegar or baking soda, but for more severe or persistent cases, it's best to call in a professional cleaning service. They can properly identify the root cause, use specialized cleaning products, and ensure the mildew is fully removed without causing further damage to the windows.