After many trials and errors (including some of the recommendations cited in the responses), I think I determined the cause of the problem. I had been using Nikon Transfer 2 to download the images from my D700. I therefore did the same with my new D800, with the results outlined in my orginal post. I then tried View NX2, and the images loaded and displayed normally in both my folders and when using Capture NX2.
As Eric indicated, the images now show much greater resolution than those from my D700. Thanks to all for taking the time and effort to help with my problem.