If I purchased new exterior doors and new exterior windows for my 70 year old home, would that be considered Improvements related to new Construction or not?

That would qualify for the Home Improvement Energy Efficiency Credit.   It would not be new construction, it would be home improvement.

The Home Improvement Energy Efficient Credit is a non-refundable credit

• Worth up to 30% of costs with a maximum credit $2,000 for
  • Air source heat pumps
  • Heat Pump Water Heaters
  • Biomass Stoves or Boilers
• Worth up to 30% of qualifying costs for a maximum combined total of $1,200 for the following:
  • Doors, Windows and Skylights
  • Insulation
  • Natural Gas, Oil Propane Water Heaters
  • Furnaces
  • Boilers
  • Central Air Conditioners ($600 maximum Credit)
  • Electrical Panel Upgrades
  • Home Energy Audit (up to $150)
• You can combine the $2,000 credit with the $1,200 credit for a total of $3,200
• This credit is a use it or lose it credit.  If you do have enough tax liability in the year you buy and install the item, you will not be able to carry the credit forward.
• NOT available for new construction.

Don't overthink things.  Improvements to a 70 year old home are NOT related to new construction.

The question is asked because the energy efficient improvement interview combines 3 different types of credits, some of which only apply to renovations of existing homes, and some of which apply to renovations and to new construction.  Just give the obvious answer and move forward.