Firmware HTC Desire 21 Pro

OS: Android v10 (Q)

CPU: Octa core (2 GHz, Dual core, Kryo 560 1.7 GHz, Hexa Core, Kryo 560)

RAM: 8 GB

Display: 6.7 inches (17.02 cm)

Battery: 5000 mAh

Before flashing, you need
Create a full backup of the firmware.
The battery must be 100% charged.

1. Flashing your phone using CWM Recovery
2. Flashing the phone using TWRP Recovery
3. Flashing the phone using Fastboot

1. Phone flashing using CWM Recovery
The rich functionality of CWM Recovery www.clockworkmod.com allows you to perform many manipulations with the device, including rolling the firmware. By default, stock Recovery is installed in the devices, which means that first you need to install the ClockWorkMod Recovery utility itself.
The general firmware process described below is for ZIP files. Instructions: - Download the firmware you are interested in and place it on the phone's SD card.
- Turn off your phone with the Power button.
- Hold down a certain sequence of buttons on the phone body. The set of buttons may differ depending on the manufacturer of your phone. The universal option is to press the following keys.
- Press the Power + Volume up (or Volume Down) (+Home) buttons together for a few seconds.
- After that, Recovery mode will appear on the phone screen.
- Use the volume buttons to navigate through the menus and use the Power button to make your selections.
- Select 'Wipe data / factory reset' from the menu.
- Select 'Yes - delete all user data' from the menu.
- Select 'Wipe cashe partition' from the menu.
- Select 'Yes - Wipe cache' from the menu.
- Highlight 'advanced' and press the Power button.
- Select 'Wipe Dalvik Cache' from the menu.
- From the menu, select 'Yes - Wipe Dalvik Cache'.
Go back, press 'Go Back'.
- Highlight 'mounts and storage' and press the Power button.
- Select 'format / system' from the menu.
- Select 'Yes - Format' from the menu.
Go back, press 'Go Back'.
- Select 'install zip from sdcard' .
- Choose 'choose zip from sdcard' from the menu.
- In the menu, select 'Yes - Install your firmware name' .
- Next in the menu select 'Reboot system now' .

2. Flashing the phone using TWRP Recovery
For those who prefer working with the utility in the form of TWRP Recovery, the following instructions for the step-by-step installation of the update in the form of a ZIP archive are offered:
- Upload the file with the firmware image to the device's memory.
- Go to TWRP Recovery. Just like in CWM.
- Perform a factory reset. When the operation is completed return to the original menu by pressing the 'Back' key.
- In the main menu, select 'Install' and select the firmware file. Click on it by dragging the slider to the side.
- The flashing process will take about 2-3 minutes.
- When the firmware operation is completed, you must click on the 'Reboot System' item, and reboot the device.

3. Flashing the phone using Fastboot
A universal tool for flashing Android smartphones using a PC is the Fastboot utility. It is part of the SDK Platform Tools, which means it is suitable for a large number of devices.
Before starting the firmware, you need to get access to the system kernel. Very often, many manufacturers block this system parameter, not wanting users to change the system files of their firmware images with their own hands. To do this, you need to unblock Bootloader. To do this, you need to study the detailed instructions for configuring and managing the command line. Before starting the firmware using a computer, do not forget to enable USB debugging of the device in the engineering settings of the device.
- First, copy the .zip archive with the image, and place it in the folder with 'ADB'.
- Put your device into fastboot mode and write a prompt in the command line: fastbooflash zip filename.zip.
- Wait until the end of the installation and reboot the device.

Thomas Nilan
Smartphone Expert

Thomas Nilan is a mobile phone expert with in-depth knowledge of the Android and iOS operating systems, who understands the settings of various hidden features that allow you to expand the capabilities of your smartphone, as well as get information about what is going on inside the phone for future repairs. He is an authority in his field, which has allowed him to become a ghostwriter for several technology publications, and he enjoys writing small mobile applications for testing smartphones.