How to root Ice Cream Sandwich (4.0.3, 4.0.4) (4.1.B.0.587 4.1.B.0.431 4.1.A.0.562)

This post is for 2011 Xperias models

--> Supported phones = Xperia Arc S , Arc and Ray , Neo V, Neo, Live with walkman, Mini, Mini Pro, Active, Neo L, Xperia Pro

     Go to settings > Security > Mark  "Unknown sources"

     Settings > Developer options > Mark USB debugging

     Settings > Xperia > connectivity > USB connection mode > select MSC mode

1. After marking the settings above, connect your phone to PC and wait for the adb drivers to be installed.
2. Download this rooting toolkit. Link >  1 / 2 / 3 /  4 and run it. It should now detect your phone and show an option to "root". Just click on it, wait till it finishes
3. Rooting done ( For confirmation see if any Super User app has been installed )

original post on XDA > http://forum.xda-developers.com/search.php?searchid=163645964