How To Unlock Bootloader in HTC phone?

Download Necessary Tools

1. HTC drivers
2. ADB mini with Fastboot tools

Install Necessary Tools and Drivers

1. Install HTC drivers to get communication with the phone.
2. Install ADB mini with Fastboot tools to get all needed tools and rest of adb drivers that are required.

Read All Necessary Information from Phone

1. Create an account on HTC page or log in if you got one.
2. Select your phone model and press Begin Unlock Bootloader button.

3. Next, confirm that you know what you do by press YES button, then check both checkbox and press Proceed to Unlock Instructions button.

4. Go to step 4 and press button Step 5.

5. Next turn the phone in fastboot mode and connect to the usb cable.
6. Turn on command prompt with admin rights.
go to c:\Adb directory on the command line:

• type the cd\ and press enter key
• type the cd adb and press enter key

7. Use command fastboot oem get_identifier_token and press enter key.
8. Next copy exactly what you see in manual on HTC page from command prompt and press submit button.

9. Next wait for an e-mail with unlock bootloader code file.
E-mail will come in next 24hours (usually it takes few minutes).
10. You can now disconnect your phone from usb cable and turn it off until you get an email.
If you didn't receive an e-mail after 24 hours check spam directory.

WARNING !
Bootloader Unlock in the phone will erase all of your data.
All described operations you are doing at your own risk.
If want saves your data do a backup before start.
The battery should be at least 60% charged before starting.

Unlocking Bootloader Manual

1. Save unlock_code.bin file from e-mail and copy it to c:\Adb directory
2. Turn the phone into fastboot mode and connect it to usb cable.
3. Turn on command prompt with admin rights and go to c:\Adb directory
4. Use command fastboot flash unlocktoken Unlock_code.bin and press enter key.
5. If the file is right for your phone, you will get the message on screen that you try to unlock bootloader, select YES by volume up/down button and confirm with power button.
6. The phone will restart and you will get the bootloader unlocked.

That's all. Congratulations.
This is the first step to root phone, write custom recovery or write custom firmware.