I think all newbies are confused about Boot loader. The following instruction will help u and easy to do unlock.
First check ur software version 11w026 or below version.if its below 11w026 do the following instruction.
1.S1 tool http://www.mediafire.com/?iwnjno9hirpgcm1
Disable Antivirus first.
Install Gorden drivers first, then only flash tool will detect ur phone...!
Switch off ur phone.Open S1 tool and click do job. Hold back button and connected to use port,
Now the s1 tool will do the job.
Check ur boot loader unlocked or not:
you will see something like RUNNING S1_EROM VER "R8A029"
small r which means your bootloader is unlocked.
Open Mmz file and extract that.
Switch on ur phone. and Run mmsc_semc.cmd..It will start to Unlcok the bootloader.
Wait till finish. Now ur phone will be unlocked successfully.
You r the only responsible if ur Awesome xperia bricked..
Like Do not Run MMSC-SEMC2.CMD. It will lock ur sim certificate..
If ur have problem in Sim Like"No SERVICE" after unlock the boot loader, Re lock the boot loader and do it again..
Be Careful..Its your own risk,,You are the only responsible,If ur lovely xperia Bricked..!
Relock the boot loader Tools:
Relocking bootloader steps:
Launch the s1tool.exe(Link Given Below)
Click restore button on s1tool
Turn off the phone
Connect your phone in flash mode (press back button while plugging your usb untill green led blink)
Wait till it finished relocking your bootloader.
The phone will restart
Check Bootloader Relocked:
Repeat the step above but on no 2 step you choose identify not restore if the previous relocking process successful you will see something like RUNNING S1_EROM VER "R8A029" notice the CAPITAL R.
Unsuccessful - you will see it with small r which means your bootloader still unlocked.
Flash stock kernal and stock rom
And also Spl thnx to CtrlAltDelIrl,sgt. meow,fotak-x,IAmNice(Giving a nice idea to update this thread..)