Why does my windows sweat in winter time?

Question

Why does my windows sweat in winter time?

Answer 1

The window is very cold due to it's contact with the outside air.  The inside air that is in contact with the window is cooled enough that the water vapor in that air condenses onto the window surface.  It's the same process that causes water to form on the outside of a cup containing ice or a cold liquid.

Answer 2

are you using XP or Vista?

Answer 3

the difference in temperature between ins and out ,make that msinse water particle tend to escape,it founds ur windows which sticking on................