Thank you for your feedback on JELD-WEN. We apologize for your frustration and can assure you we take your product concerns seriously. It is unfortunate that the differences between v4500 double hung and v4500 single hungs were not demonstrated or explained to you as they are real and for the most part as you described related to material, balances, screens, and etc. Vinyl Windows are manufactured in a factory environment using saws, drills, punches, and other manufacturing equipment that may contribute to some dust. Some of this dust may remain on and in the product until the window is cleaned following installation and final inspection in your project. There is some material left on the corners of the vinyl frames to maintain the integrity of the welded and sealed corners of the frames. Some excess material is normal, expected, and should not affect installation or finishing. The v4500 double hung features two sash on balances that allow for upper and lower sash to operate up/down as needed. The v4500 single hung only allows for the lower sash to operate up/down on similar spring loaded balances. The v4500 double hung can use "constant force" balances while the v4500 single hung uses "block and tackle" balances which are also tested and certified for window function and operation. The v4500 single hung window is also known as a sash side-load window vs a sash tilting window. Occasionally during shipping, handling, or installation, the sash may become dislodged and need to be reset to correct. Instructions for this are located on the window or may also be found on our web-site at www.jeld-wen.com. If you find after all is said and done that a not-installed window is defective or damaged beyond ability to use it, please return for refund and do not install. If you need and would like replacement parts such a screen, lock, or balance, please contact HomeDepot.com customer support as they have a process to obtain replacement parts for orders and we ship directly to customers. If you are keeping the products and/or have already installed but a potential defect remains please proceed with warranty request with us on this product. Please complete our Online Service Request Form at this link: http://www.jeld-wen.com/en-us/product-support/customer-service/service-request. A Customer Service Representative will contact you within two business days.