AT&T Atrix 4G with and UNLOCKED bootloader
Windows OS x64/x86 (Windows XP/Vista/Windows 7 - it should work on this OS)
Motorola drivers must be installed
Put your device in Fastboot mode by holding the volume down button while booting then volume up.
If you followed the steps correctly you should have Gingerbread 2.3.4 on you AT&T Atrix.
On your PC or Computer or Laptop: Use this command
On Windows START Menu, click the RUN command and type CMD (the Windows Prompt)
Type this commands (one at a TIME)
cd C:\moto-fastboot
moto-fastboot flash boot atrix-2.3.4-hktw-boot.img
moto-fastboot flash system atrix-2.3.4-hktw-system.img
moto-fastboot -w
moto-fastboot reboot
Download the .zip file here and extract on your drive C:
This guide will avoid your from boot looping.
