Rooted Xperia ARC (LT15i .181 HK/Global)

1. Download:
-fastboot package: http://www.multiupload.com/BMJ24IL6XY
-32/64bit drivers: http://www.multiupload.com/0XZV1LXRVA

2. Go to: http://unlockbootloader.sonyericsson.com/instructions
3. At the bottom click 'Continue' and enter your IMEI (type *#06# to find out), name and email address
4. You should now receive your unique unlock key
5. Extract fastboot.rar and open fastboot folder
6. Hold SHIFT and right click on the background of the folder
7. Select 'Open command window here'
8. Connect your phone in fastboot mode (turn phone off, hold menu button and plug in USB Cable)
9. In the cmd windows type in fastboot.exe -i 0x0fce getvar version
10. If a value is returned, it means the phone is correctly connected
11.Type in fastboot.exe -i 0x0fce oem unlock 0xKEY and replace KEY with the key provided in step4
12. You're device should now be bootloader unlocked

Then, download the system image you needed:

LT15i_3.0.A.2.181_Global_Customize_system.zip (153.16 MB)
http://www.multiupload.com/QUKXOPW7MG
http://u.115.com/file/t7934273b

Downlaod the Android SDK (android-sdk_r10-windows.zip) via http://developer.android.com/sdk/
Extract android-sdk_r10-windows.zip to C:\
Extract the system.zip file to C:\android-sdk-windows\tools and you will get the SYSTEMFILE.img file. (Filename will get different)

Unplug the USB cable and power off the phone

Press the "Menu" button and plug the USB cable.


After that you will see the BLUE Notification light.

Go to the Start menu and click Run. Type cmd and press enter.


Type

Code:

cd \android-sdk-windows\tools
fastboot devices

and press enter.

If you got XXXXXXXXXXXXXX fastboot that means your phone successfully connected.


Then, you can flash the system img to phone.
Type

Code:

fastboot flash system SYSTEMFILE.img

and wait a few minutes. (Please change SYSTEMFILE.img to the file your have extracted)


After Flash operation complete, reboot the phone!