Replacement
  Why replace your windows?  The first situation is you may have a window that can’t be restored or repaired for 
  less than replacing it.  You may also consider window replacement to take advantage in the advances in 
  energy savings in new high-performance windows.  In many cases ENERGY STAR windows will pay for 
  themselves by saving on your energy bill.  And another reason to replace your windows is to improve the 
  appearance and resale value of your home.  New windows improve curb appeal, increase resale value and 
  can reduce your heating and cooling cost.