The instructions at the foot of the
Library-download page, say this:
When you have downloaded the Library book (.sudbook file) to your computer, place it in the directory where your Sudoku library books are stored. If you don't know where that is, go to the File menu in the Sudoku program and select "Set Directories..." You will see the directory for Library books. That is where you should put the library book.
I guess the part at the end may need clarifying. Once you know the name of the directory where your Library book files should be placed, go into Windows Explorer (not Internet Explorer) and move the Library book
from the place to which you downloaded it
to the Library book directory.
In fact, if you know the name of the Library book directory already, it would be best to download the Library book from the Internet straight into the Library book directory.
If you have never moved the Library book directory since you installed the Sudoku program, the directory will be called "Library" and it will be found in the same directory as your main program file (sud.exe) - and that is probably in C:\Program Files\Pappocom\Sudoku.
The Library book has the ".sudbook" extension. If at any stage it gets changed (e.g., to ".xml"), change the extension back to ".sudbook".
Does any of that help?
- Wayne