While you wait for the download to complete, please consider contributing to support the development
of calibre.
If you are using Windows 8, please use calibre 5.44, which works with all Windows 8 machines,
from here
.
Simply un-install calibre and install 5.44, doing so will not affect your books/settings.
If you are using Windows 7 or Vista, please use calibre 3.48, which works with all Windows 7/Vista machines,
from here
.
Simply un-install calibre and install 3.48, doing so will not affect your books/settings.