Visit this link:
http://www.sonymobile.com/us/tools/pc-companion/Click on Download PC companion
Run the software
Turn the phone off and disconnect it from the computer
1. Disregard any instructions to connect the phone until you complete step 9
2. In the welcome screen you will see the different modules available for you including the "support zone" option. Click on "Start" below it.
3. On the next page Click on "Start" under "Phone/Tablet Software update"
At this point if you get an error stating that "unable to install update components" or "server is bussy" Please proceed to step 12. If you not see that error then continue with step 4.
4. The program will show a window saying "Could not find phone/tablet". Click on the option below that reads: "Repair my phone/tablet" the program will issue you a warning on the content that you will lose during the update
5. Choose the option to continue.
6. The program will issue a final message warning you of possible data lost during the update. Click on the checkmark and then on "Next/Continue".
7. After that, the program will download the necessary information (5 to 6 minutes) and it will present you with a list of phones.
8. Choose the Phone from the list then click on "next" then you will see a new section telling you how to connect the phone. (don't connect it yet)
At this point the phone must be off and disconnected from the PC.
9. Connect the cable to the PC not to the phone, then wile pressing and holding the indicated button (in the steps on screen an specific button will be shown for you to press on the phone) connect the cable to the phone and keep holding the indicated button until the program says "the update of your phone has started..." (in some cases a message of "Installing drivers" will appear before the message of "the update of your phone has started..." is shown.)
10. If you failed to follow the steps correctly the phone will turn on and it will request that you "Proceed with the following steps, slide down the notification bar", If this happens disconnect the phone from the cable, turn it off and repeat from step 9).
11. If the phone is connected properly, PC Companion will proceed with the update ( It will tell you to let go of the back key) then wait for the update to finish and follow instructions on screen to disconnect the unit.
12. If "unable to install update components", close Pc companion and. Install Java from:
http://www.java.com.Start Pc companion again and try to do the software unlock process once more.