Unlocking your bootloader is to partially remove some of the default restrictions in the ROM of your device: to have access to overwrite commands, mount, read and write system partitions. Be reminded however, “that not all claims resulting or caused by or from the unlocking of the bootloader may be covered under warranty – HTC.”
- Back up all your User Apps and Data using Helium.
- Back up all personal files (music, pictures, videos, docs etc).
- Download and install HTC Sync on your computer.
- Download and install Fastboot and ADB files and drivers.
- Make sure your device is at least 70% charged.
- Enable USB Debugging.
- Disable Fastboot in Power Settings (If your device is running KitKat or lower).
- Sign Up for an account on HTC Dev.
Now that you’ve satisfied all the above prerequisites, follow each of the following steps keenly and systematically to avoid damaging your device.
Step 1: Turn Off your device and boot it into Fastboot Mode (i.e. by pressing the Volume Down Key and the Power Button). You should see the screen below if you do that correctly. If your device boots normally, turn it off and repeat the process until you see the screen below …
Step 2: If the Blue highlight is already on FASTBOOT, press Power Button to select it. If not, use Volume Keys to navigate up or down until Fastboot is highlighted, then press the Power Button to enter into Fastboot Mode.
Step 3: Connect your USB Cable to your phone (first), then connect it to the computer. If you have successfully completed Prerequisites 3 & 4 above, you should see “FASTBOOT USB” as shown below:
Step 4: Locate the “adb” folder created on your computer from completing Prerequisite 4.
Step 5: In the adb folder, press the shift key and right-click on any free space in the folder. Select “Open command window here” … the command widows should show up.
Step 6: Now type the command: fastboot devices. A list of connected devices will show up. You should see the Serial Number of your device, if you completed Prerequisite 3 & 4 successfully.
Step 7: Now visit http://www.htcdev.com/bootloader and log in with the account you created in Prerequisite 8. Select “All Supported Models” from the list, accept all terms and conditions to proceed to the next level.
Step 8: Step 1 to 4 on the site has been successfully completed if you have followed this guide to this stage. Click on Proceed to Step 5 and follow the steps which will show up on the page.
Step 9: If you followed our guide and the rest of the steps from Step 5 on the htcdev site to the end, you should have your device rebooting to factory default, with an unlocked bootloader. Verify that your device now has an unlocked bootloader by powering it off and booting it into Bootloader Mode (Power Key + Volume Down).
So that’s it! You have successfully unlocked the bootloader of your HTC One device. If you had any challenges executing any of the steps, or couldn’t unlock your bootloader successfully, feel free to ask for more help in our comments section below and we would gladly assist you.