samsung Galaxy S3 UMTS to unlock

nvram rebuild:

just flash a TW rom. (example)

Once you are in stock ROM and gotten through all the annoying pop-ups, open your dialer and type in *#197328640#
it should open up a menu, you want to go to Mainmenu > UMTS > Common > NVREBUILD > NVREBUILD > Once you select to rebuild the NVRAM and it finishes don't exit the menu wait about 30 seconds long press power button and select Resta.

 To unlock your Galaxy S3 OR NOTE 2:

To unlock your Galaxy S3 OR NOTE 2:
Attention S3 users, you need to update your S3 to 4.1.1 Jelly Bean which was released today December 3 by Samsung in order to be able to unlock your phone.
Just dial the following keys *#197328640#

Main Menu > [1] UMTS > [1] Debug Screen > [8] Phone Control > [6] Network Lock > Options [3]Perso SHA256 OFF > (after choosing this option, wait about 30 seconds, then go back one step by pressing the Menu button then select Back, now you are in [6] Network Lock then choose [4] NW Lock NV Data INITIALLIZ ..... wait for a minute then reboot your phone