For all those that might purchase books from Amazon and sideload onto their Kobo please be aware that if you are running Windows 8 and download and use the Win 8 version, the book that is downloaded is fragmented into about 150 little bits, so it's impossible to sideload.
I had to uninstall the Win 8 version and install the Win 7 version which runs fine on Win 8 and also keeps the book whole in the "My Kindle Content" folder.
(Just make sure to remember to change the default folder location to your current one)
More information here
https://www.mobileread.com/forums/sho...d.php?t=236516