Dealing with Kindle for PC/Mac 1.19 (and later) and KFX in calibre

The Kindle for PC and Kindle for Mac programs use Amazon's KFX format for most books. Each book will appear in a separate subdirectory of the "My Kindle Content" folder with a file extension of ".azw". Unless additional steps are taken, these books will fail to convert in calibre with the error: "KFXError: This is an Amazon KFX book. It cannot be processed."

There are several methods for either avoiding or handling KFX format. The following descriptions apply both to Kindle for PC and Kindle for Mac unless one is mentioned explicitly.

Method 1 - Revert to an older version of Kindle for PC/Mac

Older Kindle for PC/Mac version 1.17 can be installed to work around this problem for most users. //

Method 3 - Use an e-ink Kindle instead

If you have an e-ink Kindle device registered to your Amazon account you have the option of downloading books directly from Amazon instead of using Kindle for PC/Mac.

• From the Amazon website access "Account & Lists" -> "Manage Your Content and Devices".
• Find a book you want to import into calibre and press the "..." button in the "Actions" column for that book.
• In the menu that pops up choose "Download & transfer via USB". Then select the name of your registered kindle device in the drop down menu and press the "Download" button.
• Import the downloaded file into calibre using the same procedure that you would use for a file from Kindle for PC. You will need to select the proper folder containing the downloaded file. (This folder will be different from the "My Kindle Content" folder used by Kindle for PC.)
• Users of the DRM Tools should refer to Apprentice Alf's Blog or Apprentice Harper's GitHub for information on the configuration required to support books downloaded for an e-ink Kindle. //

Obtaining and verifying Kindle for PC/Mac software

Older versions of the Kindle PC/Mac software are no longer available directly from Amazon. You will need to search online for the proper file name and download it from a third party site. The file name to search for each version is listed below.

Important: After downloading you should verify the SHA-256 hash of the file in order to avoid malware. If the hash does not match, delete the downloaded file and try again from another site. Do not install a file that has an incorrect hash!

One way to verify a hash in Windows is to open a command window, change to the folder containing the downloaded program, and enter the command:
certutil -hashfile <filename> SHA256

version 1.17/1.17.1
filename: KindleForPC-installer-1.17.44170.exe
SHA-256: 14e0f0053f1276c0c7c446892dc170344f707fbfe99b695176 2c120144163200

https://archive.org/details/kindle-for-pc-1-17-44170 //

Disable Kindle for PC Auto Update

Starting in October 2020 Kindle for PC has become more agressive about updating itself, even if the option to automatically install updates is deselected. One method to block automatic updates is to locate the "updates" folder within your Kindle for PC installation and replace it with a file of the same name:

rmdir /s /q %LocalAppData%\Amazon\Kindle\updates
echo  This file disables Kindle for PC downloads. > %LocalAppData%\Amazon\Kindle\updates