Seal failure is pretty common with cheap windows. What happens is that the Argon Gas gets out or if they have oxygen inside that gets out, you get moisture in it. It's bad for windows. Typically, you have expansion and contraction and a lot of times they have a metal piece in there and that drags the metal. It's kind of like a flat tire on your window and you can't fix it. What’s worse is that you get condensation inside the window. You can also get bugs, spiders, or anything that crawls inside. If that ever happens to you, it’s time to get new windows.