In case you wish to taste what the Nougat will offer and how it runs to your beloved HTC One M8 then I invite you to install CM14 based on Android 7.0 to your One M8 device.
And remember that CM14 ROM is not an official stock firmware released by HTC instead it is a modified ROM made from AOSP released by third-party Android developers that have nothing to do with HTC.
- Your device's bootloader should already be unlocked.
- You need to already installed TWRP recovery image.
- You need to firstly make backups before proceeding.
- Enable USB debugging mode of your HTC One M8 device.
- Your device warranty will be nullified for installing this modified ROM.
- A computer with a USB cable to transfer the CM14 ROM zip file to your device.
- Charge your batter power if it's in low power.
Follow all the instructions on this post but keep in mind that all the possible risks which may happen or during the flashing procedures are your responsible.
How to update HTC One M8 to Android 7.0 Nougat using CM14 ROM and TWRP recovery
- You need to download the Android 7.0 CM14 ROM to your PC.
- After that, you need to move the ROM zip file to your device's internal storage by connecting your device to PC using a USB cable.
- Now power off your device then disconnect it from USB cable.
- Then power on your device while your fingers press and hold these buttons; Volume Down + Power. (This is for accessing the Recovery Mode).
- Once you are inside the Recovery Mode / TWRP Mode, just perform the full data wipe by selecting the Wipe button, and then swipe this -> Swipe to Factory Reset option.
- Now back to TWRP main menu to further selecting the Install button. On the list, you can select the CM14 ROM zip file you moved to your device's internal storage.
- Confirm the installation on the next screen and do not forget to swipe the Swipe to Confirm Flash option. This will start the installation.
- The installation will complete and the screen will look like this.
- Now tap Wipe cache/dalvik button if you somehow facing the bootloops or other technical issues.
- After that, just reboot your device by utilizing the Reboot System option on TWRP.
Well done my friend because you have just installed CM14 Android 7.0 Nougat on HTC One M8 of yours. Verify it by simply going to Settings -> About Phone.