How To Remove Device May be Associated With Existing Mi Account

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Today my friend got the above warning in his Xiaomi Mi M3
He said he did a hard reset and after boot phone stuck on the Mi Account activate screen. Unfortunately, he doesn't have a Mi account associated with the device to complete the activation.
I did hard reset again, no luck still prompt the same warning.
Found many recommendations by Google search, but none worked as expected. Finally solved the issue by erase the config on fastboot mode.

Be aware that by erasing the config you may lose Browser, Chrome, Google, Google Play, etc., you need to install all of them manually.

Steps...

•  Download and extract the Fastboot.zip
• Open CMD then navigate to the extracted folder (Simply open the extracted folder then shift+right click and select Open command window here) or download minimal adb and fastboot setup
• Now boot your phone to fastboot mode (Volume down + Power button)
• In fastboot mode connect the phone to computer.
• In CMD execute the below commands in the given order

fastboot devices

fastboot -w

fastboot erase config

fastboot reboot

Wait till the phone boots up. That’s all.