RECOVERY
 
1)  
Download the latest MIUI ROM file Download here
Rename the downloaded ROM file to ‘update.zip’ on the computer.  
 
2)
Connect your device to the Windows PC/laptop via a micro USB cable, and copy the ROM file downloaded and renamed in Step 1 into the root directory of the internal storage of your device. (Do not put it in any folder)  
 
3)
Enter the Recovery mode of your device. There are 2 methods to do it as follows:
Method 1: Launch ‘Updater’ app on your device, click the ‘…’ icon at the top-right corner, and select ‘Reboot to Recovery mode’ to enter.
Method 2: You can also turn off your device and then hold both Volume+ button and Power button at the same time to enter Recovery mode.
 
4)
In Recovery mode, you can use Volume +/- to select up/down, and Power button to confirm.
After entering Recovery mode, choose the language you use, select ‘Install update.zip to System One’ and confirm, and then your device will begin updating automatically. Wait until the update is completed, choose ‘Reboot to System One’, and then your device should boot to the new version.

FASTBOOT
 
1) Download MIUI ROM Flashing Tool (Size: 46 MB)
 
2) download MI8 fastboot rom
 
3) Turn off the device. Press the Volume– key and the Power button at the same time to enter Fastboot mode. Then connect the device to the Windows PC/laptop via a micro USB cable
 
4) Double click on the downloaded ROM file to decompress it. Open the file folder for the decompressed ROM pack, and copy its path on the computer.
 
5) Decompress the MIUI ROM flashing tool downloaded in Step 1, and double click on it to install (if there is security warning, select 'Run'). After installation is completed, open MiFlash.exe and paste into the address bar the ROM file folder path copied in the last step.
Click on the first button (circled out in yellow) to Refresh, and MiFlash should automatically recognize the device. Then click the second button (circled out in red) to flash the ROM file to the device.
 
6) Wait until the progress bar inside MiFlash turns fully green, which means the ROM has been successfully installed. Then your device should automatically boot to the new version.
 
6bis ) If the flashing guide could not help you, please download Mi PC Suite here
(After Mi PC Suite is installed, make sure that your phone is in fastboot mode, connect your phone to a computer, and select the correct ROM file to flash)