My husband and I purchased Stanek replacement double-paned windows for our home 5 years ago. We went with Stanek because they had been in business a long time and had good reviews/ratings and a lifetime guarantee. Quite a few started to fail soon after. Stanek then sold the company to Great Day and the new owners will not honor the guarantee. About 50 percent of our windows have failed now and we will have to pay thousands of dollars to replace them. they are still marketing and selling windows under the name Stanek, but insist the company no longer exists and will not help us.