[jhowell]

Originally Posted by DNSB

As an alternative (thanks, jhowell!), I did a batch file that kicks off Kindle for PC, waits 10 seconds and then imports the deKFX.reg file.

I modified your .cmd file to not require a separate .reg file and to poll the registry and patch the value once Kindle for PC has set it. That should make it work more quickly on fast systems and prevent it from failing on slow systems.

The file is attached for testing. Unzip and run. (On some systems you may need to unblock it by right clicking, selecting Properties and then in the dialog checking Unblock then OK.)

Spoiler:

reg delete "HKEY_CURRENT_USER\SOFTWARE\Amazon\Kindle\User Settings" /v "isKRFDRendererSupported" /f
start %LOCALAPPDATA%\Amazon\Kindle\application\kindle.exe
:repeat
timeout 1
reg query "HKEY_CURRENT_USER\SOFTWARE\Amazon\Kindle\User Settings" /v "isKRFDRendererSupported"
if ERRORLEVEL 1 goto :repeat
reg add "HKEY_CURRENT_USER\SOFTWARE\Amazon\Kindle\User Settings" /v "isKRFDRendererSupported" /t REG_SZ /d "false" /f

(Attachment removed. See this post for the latest version.)