How to reflash Xiaomi Redmi 9 through your computer: the full guide

The MIUI operating system installed on your Redmi 9 may eventually start to run unstable, causing freezes or unexpected reboots. Sometimes a software failure after an unsuccessful “over the air” update, and in other cases, the user simply needs a more recent version of Android with new security features. In such situations, standard methods of recovery through the settings menu often prove powerless, requiring deeper intervention in the device’s file system.

The process of flashing through a personal computer is the most reliable way to bring a smartphone back to life or completely clean it of system debris. Using a wired connection ensures stable data transfer and minimizes the risks of interruption, which is critical for the integrity of the bootloader. In this article, we will detail each step of preparation and execution of the procedure so that you can safely update or restore your gadget.

It is worth noting that a complete flashing through Fastboot completely removes all user data from the internal memory of the device. Make sure to back up photos, contacts and important documents in advance, as it will be impossible to return them after formatting without a prior backup.

Preparation of equipment and software

Before you start taking action, you need to collect all the necessary tools. You will need the Xiaomi Redmi smartphone itself. 9, fit USB-cable (preferably original or certified, as cheap cables often do not provide the desired data rate) and a computer running the Windows operating system. ADB Fastboot, which is often included in the platform SDK or installed separately through the installer driver_installer.exe.

The key to getting ready is to download the correct firmware file. Redmi 9 has different versions: Global, European, Russian and China. It is important to download the version that corresponds to the region of your device or the one you want to go to. The firmware file for your computer usually has the.zip extension and weighs from 2 to 4 gigabytes. After downloading, you need to unpack the archive to the root of the disk or to the short-path folder to avoid errors when reading the paths to the files.

You will also need a dedicated utility, the Mi Flash Tool, which is the official software from Xiaomi, designed to install system images, download it only from proven resources or the official MIUI forum to avoid malicious code. Once you install the program, make sure that it is correctly displayed in the list of installed programs and runs without errors.

Unlocking the loader: a mandatory stage

Most modern Xiaomi smartphones come with a locked bootloader, a security measure that prevents you from installing third-party software or changing system partitions. To reflash Redmi 9 through a computer with full data cleanup, the bootloader status must be changed to Unlocked. If you try to flash a device with a locked bootloader, the process will end in error or not start at all.

The unlock procedure requires submitting an application through the official Xiaomi website and waiting for the application to be made. 7 before 168 Once you have permission, you need to log into your Mi Account in your phone settings, turn on developer mode, and activate Factory Unlock. Only then, by going to Fastboot mode (clicking the volume button when connected). USB), we can run the utility mi_unlock.exe on the computer and perform unlocking.

⚠️ Warning: Once the bootloader is unlocked, the device will automatically perform a full Wipe Data reset, which is a security mechanism against theft. Make sure you remember the password from your Mi Account, as after the reboot, the phone will require you to enter it to confirm ownership.

There are nuances associated with account binding: If you try to unlock your device immediately after you submit your application, the system will issue an error, you must maintain the time interval specified in the security application, and some regional versions of firmware may have unlock restrictions, which requires additional attention when choosing a method.

Selecting the type of firmware: Recovery or Fastboot

Users are often confused about the types of updates available. Redmi 9 has two main firmware formats: Recovery ROM and Fastboot ROM. Recovery ROM has a.zip extension and is designed to be updated via a recovery menu or built-in updater. This method saves user data (when selecting the appropriate item), but does not allow you to change the firmware region (for example, go from China to Global).

For our purposes, when you want to reflash the phone through a computer with a complete cleaning or change of region, you need a Fastboot ROM. Such files have the extension.tgz and contain full images of all parts of the system: boot.img, system.img, recovery.img and others. The weight of such firmware is much larger, and the installation process requires the presence of an unlocked bootloader.

Below is a table to help you identify the differences and choose the right file:

When downloading firmware, pay attention to the encoding of the name. For example, for the global version of Redmi. 9 (codename merlin: The file name will contain merlin_global. If you see merlin_ru, This is the Russian version, and merlin_cn — Installing Chinese firmware on a global device without prior preparation could lead to notification problems and a lack of Google services.

Installation of firmware through Mi Flash Tool

Once all the preparatory steps have been completed, the firmware file is unpacked and the bootloader is unlocked, you can proceed to the main action. Launch the Mi Flash Tool on behalf of the administrator. In the top field of the interface, you must specify the path to the folder with the unpacked firmware. Press the refresh button, and your device, identified by the serial number, should appear in the list.

At the bottom of the program window, you'll see three options. The most important one for us is clean all. This mode completely clears the internal memory and installs a clean system. The save user data mode will try to save files, but it often leads to errors when changing Android versions, so it's not recommended. The third option, clean all and lock, not only flashes the phone, but also re-locks the bootloader; use it with caution, because when you run a non-origin region, this can turn the phone into a brick.

Now, put Redmi 9 in Fastboot mode. Turn off the phone completely. Then press the volume button and hold it, connect the USB cable to your computer. The smartphone screen will show an image of a rabbit fixing an android and say FASTBOOT. Once the device is determined in the program, press the flash button in the Mi Flash Tool.

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Use a USB 2.0 port on the back of your computer. USB 3.0 ports (blue) on older motherboards sometimes cause timeouts when transferring large amounts of data, which interrupts the firmware process.

It takes 200 to 600 seconds. Don't touch the cable or turn off your computer. The program log will show you progress messages: sparse write, send, flash success. When the status bar shows success in green and the phone automatically restarts, the procedure can be considered complete. The first download can last up to 10 minutes.

Resolving errors and problems when running

Even with strict follow-up, there can be technical difficulties. One of the most common mistakes is Miss matching image and device. It means that you are trying to flash firmware that is not intended for this model (for example, the firmware for the Redmi 9T on Redmi 9).

Another common problem is driver error, where the computer can't see the phone in Fastboot mode, even though the connection sound is heard. QHSUSB_BULK Or a device with a yellow exclamation point, in which case you need to manually update the driver by selecting a file. android_winusb.inf file-box SDK Platform Tools or Xiaomi Driver Installer.

⚠️ Attention: If there is a firmware error and the process is interrupted, do not turn off the phone. Try pressing the retry button in the program or reconnecting the cable with the volume buttons. In 90% of cases, the process can continue without losing data if the images have already been partially recorded.

Sometimes users encounter an “Anti-rollback check failed” error, which is a rollback protection for the software version. You can’t install an older version of Android or firmware than the one installed now if the anti-rollback was activated by the update. Trying to do this will lock the device. Always check the anti-rollback version before installing custom or old stock firmware.

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The success of the firmware depends on quality USB-cable and correctness of the selected file ROM. 80% of errors are caused by using a damaged cable or firmware from another phone model.

Initial data setup and recovery

After successfully installing the new system and first downloading, you will be greeted by a welcome screen. The interface language will most likely be set by default (often English or Chinese if the firmware is Chinese, but we are considering Global ROM).

It will ask you to log in to Google and possibly Mi Account if you haven't logged out before resetting, which is a standard FRP (Factory Reset Protection) procedure, and if you don't remember passwords, it's going to be extremely difficult to restore access, so make sure you have them before you start flashing.

In the “App and Data Copy” phase, the system will prompt you to restore a backup from the Google cloud or from your Android device. Choose the right option to return contacts, settings and applications. If you have made a local backup through Mi Cloud or third-party funds, it can be restored later through your phone settings.