How to unlock bootloader of Htc desire 820

Currently two methods available for Unlocking bootloader of htc desire 820 :-

Note :-  I am not responsible for any damage or brick of your device using this methods. You should use this methods on your own risk, lf you don't know what you're doing, don't do this.

Method 1 :-

 Prerequisites :-

* WinDroid Universal Android Toolkit
* Supported Device (At least 50% charge)
* Windows XP - 10
* USB Cable

Initial Setup
1. Open the WinDroid Universal Android Toolkit.
2. Download and install the ADB drivers if it prompts you to.
3. Choose your device from the list. Wait a few moments while it downloads the correct recoveries.
4. Turn on your device, go to Settings > Developer Options and Enable USB Debugging and plug it in. If the toolkit does not recognize your device immediately, click on the Refresh button in the bottom right corner.
- If you are on Android 4.2.2 or above, and you do not see a button for Developer Options, you will need to go to Settings > About > Software Information > More and quickly tap on Build number multiple times until it tells you that Developer Options has been unlocked.

1. Click on the Get Token ID button in the Unlock bootloader box. This will reboot your device into bootloader,retrieve your token id, and open a text file contains token id.
2. Now you can submit it to Htcdev, which is open in background.
3. Please login to your account in htcdev or create one with valid address.
4. Once you logged in your account, scroll down to end of page and paste the previous token id you get
in the box My Device Identifier Token.
5. Click submit and wait until htc send a email on your email account registered with htc.
6. Once you received the email, download attached file named unlock_code. bin
7. Now click on the button Unlock bootloader, the toolkit will reboot your device into bootloader and a prompt message will appear confirming if you like to unlock your bootloader.

Note :- READ MASSAGE CAREFULLY AND BACKUP YOUR ALL DATA FROM INTERNAL STORAGE, BECAUSE IN THIS PROCESS ALL YOUR DATA AND INTERNAL STORAGE WIPED.

8. Now click up volume button once and then power button once to confirm unlock bootloader. Your device now reboot.
 Your device bootloader now unlock, you may now flash custom recovery.

Flash Custom Recovery
1. Move to the next box on the right named Flash A Recovery You now have two methods available to flash a recovery.1. Automatic Method (Recommended)
- You are given different options for recoveries depending on your chosen device. Please choose the correct device variant. This means that if there is more than one recovery option, match the one that corresponds with your carrier/model/country, etc. If you are not sure which option you should choose, please research some more or ask in this thread before you move on.
- Once you have made your choice, click on the Flash TWRP button for the correct variant. Your device will then reboot into bootloader and flash your chosen recovery.
2. Manual Method
- If you are having any issues with the automatic method, such as missing recoveries, you can download them manually here. Find the folder that matches the name of your device, then download all the recoveries within the folder. Then, move those files into the folder named Recoveries within the Data folder created by the toolkit. Finally, you can proceed with the instructions given for the Automatic Method. (If your device has only one variant, the file should be named Recovery.img. If it has two or more variants, the files should be named Recovery1.img, Recovery2.img and Recovery3.img).
You are now rocking a custom recovery! You can now proceed to gain permanent root.

Gain Permanent Root
1. Move to the next box on the right named Gain Root.1. Click on the button named Flash SuperSU and select Yes.
2. SuperSU will now begin to download. Once it finishes, SuperSU will be pushed to your device and your device will be rebooted into recovery.
3. Once your device has booted into recovery (TWRP), tap on Install in the top right corner. Then, scroll until your find SuperSU.zip. Tap on it, and swipe to confirm flash.
Congratulations, you are now fully rooted!

Method 2:- 

Download The HTC unlock bootloader tool and process as per guide below.


Enable USB Debugging.

Connect your device to PC via USB cable. It is highly recommended that you use the original cable and plug it into the motherboard port.
Select your Android version and then follow the instructions as shown to enable USB Debugging.
After that, kingo will automatically install the device driver and establish connection with your device. Please be patient.


Read the Notifications
It is IMPORTANT that you read the notifications carefully to avoid trouble later on .
You have to be fully aware of the CONSEQUENCES before unlocking your Bootloader.
Which includes your WARRANTY CLAIM being voided and USER DATA being wiped off.
Click to Unlock
Click "Unlock" to start when you are ready.
It will take a few minutes before the whole process is complete.
During this course, please do not disconnect, move or touch your device in any way.


Unlock Succeeded!
Normally the unlocking process will go fine and succeed at last. Click "Finish" and wait for your device reboots itself so that your phone will be more stable.