So this is somewhat of a science question, and I'm not a scientist. If I'm not wrong, dew is only for outside the home, for example, on plants and grass. I have never heard 'dewing' before, it's a lot less commonly used. Condensation would be the thing that happens on windows inside. Dew is a type of condensation, so 'dew condensation' is repetitive (like saying 'catfish fish'). You could just say 'dew' and it would mean the same thing. Anything with 'window' and 'dew' together doesn't make sense because dew is found on plants and grass. For windows, you only use 'condensation'. Hope that helps! If you have more questions, click on my profile and schedule a lesson. I am an English tutor currently offering lessons at a low price!