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

[DNSB]

Originally Posted by jhowell

Since first book on your list was under a dollar I bought a copy and tried it on my Windows 10 PC using Kindle for PC version 1.26. I was able to download it in KFX format without any error.

I can't explain why it does not work in your system. Possibly something to do with the VM?

I tried it on a Windows 10 Insider Preview VM with Kindle 1.26 and the file downloaded and was readable. I'm wondering if @mexofeed1 had somehow disabled KFX downloads since I got the same error message as he saw on my Windows 10 install with KindleforPC 1.24 with rendertest.exe renamed.

[DNSB]

I did some more digging at the issue. I managed to duplicate the Your Kindle App needs an update to download using Kindle for PC 1.26.

This required a 2 step process.

After opening Regedit, I went into HKCU/Software/Amazon/Kindle/User Settings and changed the value of isKRFDRendererSupported from true to false. At this point, it looks fine but as soon as you open Kindle for PC 1.26, the value gets changed back to true.

To prevent this from happening, again in Regedit, right click on User Settings and then Permissions. In Permissions, click on Disable Inheritance. This will ask if you want to do with current inherited permissions. Click on the Convert Inherited Permissions into explicit permissions on this object. Once that is done, step though the listed users, double click on any that don't show Read as the Access and remove the check mark from Full Control leaving the one on Read.

Perhaps not oddly this seems to block all KFX downloads for K4PC 1.26 and 1.28.

Edit: Also checked with Kindle for PC 1.29.58059 and still did not get KFX files though I did re-enable Full Control for System, my user and Administrators before the install and removed Full Control after the install. Without that, the install seemed to work but Kindle for PC came up still saying it was 1.28.55076.

[lkmiller]

Originally Posted by DNSB

Perhaps not oddly this seems to block all KFX downloads for K4PC 1.26 and 1.28.

...Also checked with Kindle for PC 1.29.58059 and still did not get KFX files

Woo hoo! Thanks for this. I'll keep using K4PC 1.17 for as long as possible, but good to know there's a way to prevent KFX downloads in the latest versions.

[DNSB]

Originally Posted by lkmiller

Woo hoo! Thanks for this. I'll keep using K4PC 1.17 for as long as possible, but good to know there's a way to prevent KFX downloads in the latest versions.

I'm not sure how many people are going to be comfortable with editing the registry and setting permissions.

[Terisa de morgan]

Originally Posted by DNSB

I'm not sure how many people are going to be comfortable with editing the registry and setting permissions.

Count me in, so thank you

[Sirtel]

Me too. Many thanks!

[theducks]

Originally Posted by DNSB

I did some more digging at the issue. I managed to duplicate the Your Kindle App needs an update to download using Kindle for PC 1.26.

This required a 2 step process.

After opening Regedit, I went into HKCU/Software/Amazon/Kindle/User Settings and changed the value of isKRFDRendererSupported from true to false. At this point, it looks fine but as soon as you open Kindle for PC 1.26, the value gets changed back to true.

To prevent this from happening, again in Regedit, right click on User Settings and then Permissions. In Permissions, click on Disable Inheritance. This will ask if you want to do with current inherited permissions. Click on the Convert Inherited Permissions into explicit permissions on this object. Once that is done, step though the listed users, double click on any that don't show Read as the Access and remove the check mark from Full Control leaving the one on Read.

Perhaps not oddly this seems to block all KFX downloads for K4PC 1.26 and 1.28.

Edit: Also checked with Kindle for PC 1.29.58059 and still did not get KFX files though I did re-enable Full Control for System, my user and Administrators before the install and removed Full Control after the install. Without that, the install seemed to work but Kindle for PC came up still saying it was 1.28.55076.

Maybe you can post an exported REG file for that Key.
NOTE reg files install or modify your registry. BE SURE you trust the source.

[DNSB]

Originally Posted by theducks

Maybe you can post an exported REG file for that Key.
NOTE reg files install or modify your registry. BE SURE you trust the source.

You could export/import the .reg file but that will not change the permissions on the key. In theory, the permissions can be changed by a program (the old Windows 2000/2003 regini program could do that) but by the time you open the key to see which permissions need to be changed, it's probably quicker to do it manually.

Without the permissions change, Kindle for PC will change that value back to true.

[jhowell]

Originally Posted by DNSB

Without the permissions change, Kindle for PC will change that value back to true.

It appears that it sets the value based on the results of the renderer-test program run at startup. If you launch Kindle for PC, wait a few seconds, and then update the registry the value will stick until K4PC is launched again.

[DNSB]

Originally Posted by jhowell

It appears that it sets the value based on the results of the renderer-test program run at startup. If you launch Kindle for PC, wait a few seconds, and then update the registry the value will stick until K4PC is launched again.

So if you rename the file attached to this message to deKFX.reg and import it after Kindle for PC has been started, it should disable KFX. Possibly the easiest way to test.

[DNSB]

I was doing some playing with Kindle for PC 1.29. Since my original method blocks all writes to that registry key, it does not let Kindle for PC store such things as books opened,etc.

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 tried to make the batch file generic by using variables for the Appdata/Local and user home directory. The pause can be removed when you are happy with the timeout setting (basically on my system, the Kindle app opens and then the reg import happens, your system may need a higher number depending on system speed). Both the kindle.cmd and deKFX.reg files were placed on my desktop.

kindle.cmd

start %LOCALAPPDATA%\Amazon\Kindle\application\kindle.exe
timeout 10
reg import %HOMEPATH%\Desktop\deKFX.reg
pause

deKFX.reg

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\SOFTWARE\Amazon\Kindle\User Settings]
"isKRFDRendererSupported"="false"

Both files are in the .zip file attached to this message. Unpack to your desktop and check if it works for you.

[jhowell]

Originally Posted by DNSB

Both files are in the .zip file attached to this message. Unpack to your desktop and check if it works for you.

Thanks. It works for me, but I did have to unblock both files after unzipping before Windows 10 would let me use them.

It would be nice if the .reg file did not have to be placed on the Desktop. And while Kindle for PC started in under ten seconds on my system, I can see that it might not on a slower system.

Since there is no way to detect when Kindle for PC has finished starting up I would rather just run the .reg file manually once I know it is ready.

[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.)

[DNSB]

Originally Posted by jhowell

Thanks. It works for me, but I did have to unblock both files after unzipping before Windows 10 would let me use them.

It would be nice if the .reg file did not have to be placed on the Desktop. And while Kindle for PC started in under ten seconds on my system, I can see that it might not on a slower system.

Since there is no way to detect when Kindle for PC has finished starting up I would rather just run the .reg file manually once I know it is ready.

The only reason for the .reg file on the desktop was quick and dirty. Basically, just testing the concept. As for the 10 second delay, on my system, KindleforPC flipped the value in under 3 seconds.

[DNSB]

I have noticed one issue with using the registry change after Kindle for PC launches to prevent KFX downloads. If I had made a purchase since I last ran Kindle for PC, it would start the download immediately after it finished starting up and would download the KFX before noticing the registry change. Going to Manage Your Content and Devices where I changed my default device to my iPhone keeps that from happening. If it does happen, "remove from the device" and then restarting Kindle for PC allowed manually downloading an AZW3 copy. Jhowell's modified file has a shorter wait time but still showed the issue.