I don't in fact use the courier font at all in any of my documents.
I went into the Distiller software, preferences and note that the font "Courier" is not listed in C:\Windows\Fonts but it is listed under C:\Program Files\Rapidocs, under the preferences listing. Rapidocs is a software that I downloaded this past week and it may be the source of the problem.
In My Documents, I see Courier listed as a font, but it does not appear in the Distiller Software under C:\Windows\Fonts, but only under C:\Program Files\Rapidocs. It has a different extension - it is labeled not as a TTF but as FON. I am not sure of the significance since it does appear in Distiller, albeit under a different path name,but it is suspicous as the error message in notepad is pointing to it.
Perhaps I can copy it somehow and rename it as TTF? Perhaps when I downloaded the new software, it was converted from a TTF to its own name, FON?