Rooting the Kyocera KY-42C on Windows (1.090XX+)

17 Aug, 2026

Hello! This is a quick writeup for the steps/troubleshooting/etc I went through while attempting to root the KY-42C on firmware past 1.090XX on Windows. This guide was also written up to help out the good folks on Garaho Wiki - please do join us on the Discord server if you run into issues following this guide!

This guide assumes a basic working knowledge of adb commands for navigating the phone using your PC's terminal/shell. Before you begin, please ensure the following:

• You are using Windows - this process is much more straightforward on other OSes, so if you're not on Windows please revisit Shomy's guide and start there! This guide was specifically written to deal with Windows quirks.

• You have backed up any and all important information on your phone. Please do not proceed past this point if you have not done so - there is a risk of losing data!

• You have scrcpy installed - this is NOT essential to use for this guide, but having screen mirroring set up on your PC will make navigating your phone much easier when it's time to copy and paste paths from one to the other. Installation and usage instructions for scrcpy here!

• You have developer mode turned on:

Settings -> About phone -> Build number -> Click on this 5 times until you get the message "You are now a developer!"

• You have USB debugging enabled (this lets you use adb to access your device):

Settings -> More settings -> Developer options -> USB debugging (ON)

• You have OEM bootloader unlock enabled:

Settings -> More settings -> Developer options -> OEM unlocking (ON)

Let's get started!

1. Unlock the phone's bootloader following Shomy's steps (see guide here). This blog post assumes that you are trying to root the KY-42C on Windows; if so, you will need to use Momo's edited utils.py file (download it here). Replace the utils.py file in Shomy's folder with the downloaded one (but make sure to back it up first - don't overwrite without backing it up!) and follow the guide.

There is one known issue with using Momo's utils.py file so far - apparently it does not work very well when using Penumbra. Please drop us a line on Discord if this use case applies to you and we'll see how we can help!

2. While the little animation is running in the terminal to detect your device, plug in your powered-off phone into the PC (the animation will not stop running in the terminal until you do so). Make sure you plug your phone directly into your PC (as opposed to a USB hub, etc). The script should automatically detect your phone, which will then power on by itself.

If you are running into issues and getting the INFO: waiting for device error message: make sure you have MediaTek drivers installed! Rerun the script after installation.

3. If you are successful, you should get the Orange State warning message upon reboot (right on the "docomo" startup screen; "Your device has been unlocked..." etc.) Feel free to run scrcpy at this stage if you like - screen mirroring on your PC can make the rest of the process easier!

4. Grab your phone's boot.img file, using either Penumbra to back up your .img from your phone or by using Shomy's backup boot.img which you can download here. If you are using scrcpy, you can transfer Shomy's boot.img file directly to your phone by dragging the file onto the scrcpy window; the file will be placed in your phone's Download folder.

5. Install Magisk (use F-Droid or sideload apk from GitHub).

6. Open Magisk, then patch the boot.img you pulled (or Shomy's boot.img backup):

                  Magisk -> Install -> Next -> Select and patch a file

7. Select the file to patch. Navigate to wherever you saved the boot.img and select it; I usually find it under the Download folder on the KY-42C. Patch the file and wait for Magisk to complete the process.

8. Magisk will do its thing and say All done! when it's done patching. The patched boot.img will be saved to your phone's Download folder (just like with the initial boot.img).

9. Using adb or by manually opening the phone's folders on your PC file explorer, copy the patched .img to your PC. If using adb, use this command:

                  adb pull /sdcard/Download/magisk_patched-WHATEVER STRING MAGISK NAMED IT.img

10. Reboot your phone into fastboot mode using the command adb reboot bootloader. Your phone screen will say => FASTBOOT mode...

11. On your terminal, flash your patched .img like so and let it run:

                  fastboot flash boot PATH-TO-MAGISK-PATCHED-BOOT.img

If you run into issues with fastboot and get the < waiting for any device > prompt, install the Kyocera driver here, restart your PC, and check in Device Manager if your device is detected. Once it shows up in Device Manager, you should be good to go!

12. If successful, your .img file will be flashed; both the terminal and your phone will tell you when the process is done.

13. Restart your phone:

                  fastboot reboot

14. Check Magisk to see if rooting was successful! (Under Magisk, the Ramdisk should say Yes.)

Thanks for following along! Hope this was helpful. This guide wouldn't be possible without the hard work of everybody linked throughout this writeup (as well as the folks over at Garaho Wiki - there's so much we're still learning about these phones!)

Please let me know if you run into any issues following the guide - you can also reach out to us on the Garaho Wiki Discord and we'll be happy to help :)