This software has two sequences of updates, first update will install software version 2.11.617.180 and the other will install the software version 3.35.617.12 . The first update lacks Android OS upgrade and second one includes upgrade of Android OS . Warning: Your phone will reboot several times during Updating process so do not remove the charger or press the power button for long because doing this will stop the process of upgrading and may result in bricking your device . In that case we (droidopinions) won’t be held responsible for any damage to your device.

This method here is only for HTC ONE M9. Do not try this on any other model. The process should be done by advance users only. If something wrong happens with your device durinng or after the process then will not take any responsiblity. So, try this at your own risk only. Thanks

Latest RUU file version 3.35.617.12 for HTC One M9.

  1. This guide is only for HTC One M9 . 2. Set up ADB and fastboot on your computer. 3. Install the USB drivers for your HTC One M9 on PC. 4. Enable debugging mode. Go to settings and scroll down to developers options and enable USB debugging. This was the method to update HTC ONE M9 to Marshmallow Official. If you are facing any problem feel free to let us know in the comments section below. Also share it and subscribe to out blog. Sharing buttons are below and subscription box is at the end.