Unless you are experienced, window and door installation is not a do-it-yourself project. A crack in a gas filled window will limit its effectiveness - and you won't have a warranty if anything goes wrong.   Some Common Problems: SOLUTION!! Condensation on inside glass and/or frame in fall and winter! Replace with high performance glass and/or frames!! Fading of furniture, draperies, carpeting! Replace existing glass with UV resistant glazing!! Excessive heat entering existing windows! Replace with high performance solar resistant glazing!! Existing windows conducting cold! Replace with high performance heat reflecting glass (to the interior)!! Replace existing window frames!! Cold draft through existing windows! If possible make weathertight! Replace existing window frames and glazing!! Existing window frames rotten and/or just in bad shape! Replace with energy efficient, low maintenance frames and high performance glazing!!