Sonyericsson xperia arc lt15i rooting succeed with the help of xda developers here is the screenshot and procedure
Rooting is like a main gateway which will unlock all you android's hidden abilities , it gives the user full control over your phone .Linux Super User = Android Root . Rooting is made as easy as possible , thanks to developers at XDA .
1.DooMLoRD's Easy rooting toolkit
This is an one click PC app for easy rooting created by DooMLord . Download below and extract latest 'DooMLoRD_v3_ROOT-zergRush-busybox-su.zip' file. Before you run the 'runme.bat' file
1. Make sure you have installed adb drivers (If you don't know ADB installation use any of these links LINK 1 , LINK 2 )
2. Enable USB DEBUGGING (go to settings app>Applications>Development>Usb Debugging)
3. Enable Unknown sources (go to settings app>Applications>Unknown sources)
Then connect your phone to the pc via USB cable , and run the app and follow on-screen instruction ,Do not unplug the usb cable while the APP is doing its work . and within seconds you are done. Rooting complete .
This method will install Superuser app & busybox binaries do not remove them