For those of you who want to install new ROMs like the rooted Gingerbread ROM (that I have right now), you will want to unlock the bootloader on your Atrix 4G and install permanent ClockworkMod Recovery.
This method is for Windows computers, if you don’t have one, I suggest to borrow your friend’s for couple hours.
Make sure you’ve rooted your Atrix 4g first!!!
To do this, you will need to download the atrix4gcwm2.zip file:
Unzip the downloaded folder into the root directory of your hard disk, such as c:\atrix4gcwm2.
Next, open up a command prompt by typing “cmd” under Start->Search.
Browse to the atri4gcwm2 directory by typing:
fastboot oem unlock
This will give you the unlocking code, which we will use.
fastboot oem unlock UNLOCKINGCODE
Replace UNLOCKINGCODE with the unlocking code you got earlier.
Next, flash the permanent ClockworkMod Recovery by typing:
fastboot flash recovery recovery-en-goapk-0630-1029.img
If everything went well, your bootloader is unlocked (meaning you can boot other ROMs) and you have permanent ClockworkMod Recovery.
You can check you have permanent ClockworkMod Recovery by rebooting your phone holding down both Power Button and Volume Down Button.
When you see fastboot, use the Volume Down button until you see “Android Recovery” then press Volume Up button.
Still don’t get it? Don’t worry, watch this video tutorial and you will know exactly how to do it right: