Windo.w World says that they have a lifetime guarantee and that they stand behind the quality of their windows. In my experience with them, it has been anything but that.
They have been very rude, and have given me more expensive pricing each time I have talked with them just to get a defective bottom sash window replaced that they installed.
I cannot imagine the nightmare if there were more windows involved if they will expend the amount of time and rudeness to try to avoid replacing 1/2 of a defective window. In my opinion, you should avoid purchasing from them
Review about: Window World Window.
Monetary Loss: $150.