Many home owners have difficulty deciding between repairing and replacing windows. A bargain replacements can negatively impact the value of your home. Quality custom replacements are expensive by comparison. When possible I prefer to restore existing windows and find everything I need at my local salvage shop.
Proper installation of windows (old or new) often requires the help of a qualified carpenter. I always use a professional windo glazier when replacing glass. A pro will give you a perfect painting surface and their work should last for decades.