The flagship smartphone by Taiwanese mobile manufacturer HTC One was launched with Android 4.1.2 Jelly Bean software. The latest version of Jelly Bean software, Android 4.2.2, is said to be almost ready and is expected to be rolled out for the handset sometime by the middle of this month.
Prior to the official release, the HTC One has received Android 4.2.2 on several occasions through custom builds such as AOKP, CyanogenMod 10.1 and SlimBean. To install the custom firmware, the device needs root access and a custom recovery pre-installed. But doing so voids it of its manufacturer's warranty. Users can reclaim the warranty by unrooting the handset.
Thanks to recognised XDA developer, mike1986, who has shared official Jelly Bean firmwares for different Carriers ID and an easy guide to unroot the HTC One.
HTC One users who wish to unroot their devices to go back to stock official firmware may follow our step-by-step guide.
IBTimes UK reminds its readers that it will not be held liable for any mishap. Users are also advised to verify that their devices meet following requirements.
1) Install USB Driver for HTC One to transfer files between the Android device and computer.
2) Ensure that the USB Debugging Mode is enabled on the phone to connect the phone with the computer and use the Android SDK with it. [Press Menu>> Settings>> Applications. From there navigate and click on Development option and ensure the USB Debugging Mode is turned on.]
3) As the tutorial is likely to wipe out all data of the phone, create a backup. If the device is having any custom recoveries such as CWM/TWRP installed, then users are recommended to back up the data using only the recovery.
4) The phone should be rooted. Click here for a step-by-step guide to root HTC One.
5) Verify that the HTC One has above 80% battery charge.
6) The stock official firmware work only on HTC One. Applying these to any incorrect variant is likely to brick the device.
Steps to unroot HTC One to stock official firmware
Step-1: Download stock official firmware for HTC One to the computer
Firmware download links from development page [Download appropriate firmware for the device]
Step-2: Download Fastboot. Extract the files from the Fastboot zip
Step-3: Turn off the HTC One then reboot the device into bootloader mode. To do so press and hold Volume Up and Power buttons together
Step-4: Connect the HTC One to the computer using USB cable while it is in the bootloader mode
Step-5: Open a Command Prompt window on the computer by pressing and holding the Shift button on the keyboard and right-click on any empty area on the screen, then select Open command window here
Step-6: Type the following command into the Command Prompt Window:
fastboot oem rebootRUU
fastboot flash zip firmware.zip
Step-7: When the action is completed, reboot the phone
As the HTC One boots up successfully, it should be unrooted and running on stock official firmware.
[Source: The Unlockr]