For those that have the smaller Kindle Fire HD (with the 7-inch screen) and running the latest 18.104.22.168 firmware, we have some great news. Your device can now be rooted! Rooting your Kindle Fire HD will enable you to use many of those root-only apps available on the Play Store and also take total control of your device. The guide below should help you achieve this without breaking a sweat.
1. This guide only works with the 2013 version of the 7-inch Kindle Fire HD 7 (KFSOWI) running 22.214.171.124 firmware. Do not try it on any other device.
2. Back up everything you feel is important before you begin.
3. Charge your device to 75% or more to prevent unwanted shutdowns during the procedure.
4. Make sure you have the necessary drivers installed before you begin. If not, try these.
root_script.zip [File attached to this post]
1. Enable USB debugging on your device by going to Settings > Developer options and ticking the USB debugging checkbox.
2. Connect your device to your PC. If there are any drivers being installed at this point, let them do so before continuing.
3. Extract root_script.zip to a folder on your desktop.
4. Follow the on-screen instructions.
5. Double-click on runme.bat to begin the rooting process.
Your device should have root access once it reboots. To verify, check for the Superuser app in your app drawer or install any app like Root Checker Lite.
If this procedure helped you please thank/donate to the original developers here.