Hello,
Today i will show you an easy way to root your 2011 Sony Ericsson Xperia smartphone based on MSM8255 chipset. This tutorial will work for:
2011 smartphones: Live with Walkman WT19, Xperia active ST17, Xperia acro IS11S, Xperia arc LT15, Xperia arc S LT18, Xperia mini ST15, Xperia PLAY R800, Xperia mini pro SK17, Xperia neo MT15, Xperia neo V MT11, Xperia pro MK16, Xperia ray ST18,
running Android Gingerbread 2.3.4 firmware (compilation 4_0_2_A_0_42 or older) or Android Ice Cream Sandwich 4.0.3 (firmware 4.1.A.0.562). It will work for devices with locked and unlocked bootloader.
Attention! If you want to root the latest Android 2.3.4 Gingerbread firmware 4_0_2_A_0_62 use this tutorial: E-root. If you want to root Android 4.0.4 Ice Cream Sandwich firmware 4.1.B.0.431, 4_1_B_0_587 etc. please use this: E-root or this: Vroot (Romaster) tutorial.
If you have supported device and want to root it, please follow next steps:
For Android 2.3.4 Gingerbread users:
1. Press menu button, go to Settings => Applications => Development => Enable USB Debugging,
2. Press menu button, go to Settings => Applications => Enable Unknown sources,
3. Press menu button, go to Settings => Sony Ericsson => Connectivity => USB Connection Mode => Choose MSC mode
For Android 4.0.3 Ice Cream Sandwich users:
1. Press menu button, go to Settings > Developer options > Enable USB Debugging,
2. Press menu button, go to Settings => Security => Enable Unknown sources,
3. Press menu button, go to Settings => Xperia => Connectivity => USB Connection Mode => Choose MSC mode
4. Make sure you have turned off all Sony (SUS, PC Companion) and other third party tools (like Flashtool) disabled.
5. Download and run DooMLoRD v4 ROOT: 
DooMLoRD_v4_ROOT-zergRush-busybox-su.zip 1.79MB
284 downloads
6. Connect USB cable, and when Windows will install all drivers, press any button on your keyboard.
7. DooMLoRD v4 ROOT will root your Xperia smartphone 
If you want to unroot your phone, just reflash it with any suitable firmware for your phone model or repeat root procedure using this unrooting toolkit:
DooMLoRD_v1_UNROOTING.zip 1.34MB
30 downloads
Best regards,
Jurij
Tutorial is written for Sony.yt forum. Copying is prohibited.
