[villagetinker]

How old is the house? If the reason for replacement is the windows are defective they typically have a 10 year warranty. What type of house poured concrete, block, stick, modular, etc., makes a big difference in the cost. If the house is relatively new I would go with original installer, unless you has a quality problem. If this is out of pocket, I see several window replacement firms advertised on television that claim long warranties. Tried to do this in a prior house, and the window companies were installing windows to the FINISHED window opening, NOT the rough opening. This results in smaller windows and the need for mullions outside to cover the resulting gaps. Be sure to see exactly what the companies are offering and ask for local installations that you can see.