Trust Fettig Millwork & Windows for the best window installation, repair and maintenance throughout Bismarck, Mandan, and central North Dakota. Throughout our years in business, we have gained the experience and knowledge to install and repair your windows quickly, efficiently and always completely up to code. It doesn't matter if you are only replacing one or two windows, or if you are replacing every window in your entire home or office building; we treat every job the same and we put in the same amount of effort every time.We are a locally owned and operated company that is fully licensed and equipped to provide you with the top quality window installations and repairs you have come to expect. We are proud to be Energy Star Rated and NFRC Certified. We offer a great warranty on all our services, which include parts and labor. We are proud to be the official Marvin Infinity window dealer in our part of the state. Once you learn about window options, you will understand why Marvin Infinity windows are far and away the best value on the market.