If you are looking to Bootloader Unlock your HTC One M9 as well as root it and install roms, but you are not confident with command prompts and fastboot commands you may want to check out the Windroid root toolkit. This toolkit takes all the adb fastboot commands and puts them into an easy to use toolkit. This simplifies the rooting and bootloader unlocking process making it accessible to all. Features - Many Devices Supported - Beautiful MetroUI Theme - Full Bootloader Unlock - Automatic HTC Token Retrieval - Gain Permanent Root - Flash Custom Recovery - Flash Custom Kernel - Flash Custom ROMs - Sideload Zips - Push Files - Install Apps - Relock Bootloader - and so much more! Grab the toolkit here!