In Calibre, right click on the Add Book icon, select "Add books from a single directory", navigate to the folder "My Documents\My Kindle Content", and select the ebooks you want to import into Calibre. You will first need to add the 3rd party DRM-stripping add-ons to Calibre.
It worked and I transferred the book that I actually bought from Amazon that was in my K4PC to Calibre. However, you were perfectly right, it would not let me read it or change the format because it was DRM protected. So I deleted the book.
You say I can get over this by FIRST adding the third-party DRM stripping add-ons to Calibre and THEN importing the book. Is this correct?
Have you done this yourself? Have you got easy instructions on how to add the third-party DRM stripping add-ons to Calibre?
Once the add-ons are added, when the book is then imported, will it be readable then? Or, do you have to change it to EPUB format or something like that?