Easiest way to flash ICS or Jb roms in Sony Xperia S

1. download required .ftf file first[LT26_6.1.A.0.452_Generic_CH_1257-3740_.ftf].// this is for ICS
2. then download required flashtool.exe for computer ie[flashtool-0.9.8.0-windows.exe]. of size 105 mb
3. install flashtool in computer.
4. it will make folder in C drive .  C\Flashtool
6. inside Flashtool folder there will be drivers folder, install Flashtool-drivers too which might take few time bt it is very necessary to install this.otherwise update cant be taken out
7. now inside the firmwares folder, copy the downloaded ftf file , #note- the ftf file is inside the rar file you downloaded which is of size 355mb
8. Now first plugin your xperia and run flashtool 
9. 
10. now unplug your xperia from computer  and turn off your xperia S
11. now click the flash button, on clicking the below image will appear
12. 
13. in mode selector window(a small window in left side), choose Flashmode , and hit ok button, then following window will appear:
14. 
15. again click ok button and wait until another below image comes, it might take a minute or less.:
16. 
17. now it is the time to connect your switched offed Xperia S using datacable to your computer but these below things must keep in mind.

• Keep on hold [down volume button] while connecting through USB cable 
• keep on holding for 3-4 seconds after connecting
• the above image must disapear then.
• if your drivers are well installed then your device will flash within in minute.

Cheers!!