Ice-proof your windows...with vinegar! Frost on it's way? Just fill a spray bottle with three parts vinegar to one part water & spritz it on all your windows at night. In the morning, they'll be clear of icy mess. Vinegar contains acetic acid, which raises the melting point of water---preventing water from freezing!
I got this information off of this website
I don't know if it works yet, but with weather in Colorado it won't be long. I'll let you know how it works!
Chella