You can try flashing an unbranded ROM, may be the Indian variant since they come factory unlocked. Search for instructions on flashing a ROM Lumia 920. To put it short, you'll first need to download the correct ROM using Nokia Software Updater for retail, then download the correct ROM, after that backup everything on your phone manually, and then start flashing. Remember that flashing a ROM incorrectly or wrong ROM might damage (brick) your phone so make sure you do enough reading before starting the process (it's simple but better to warn you of the consequences). Also you'll lose your data during the flash process so make sure you backup before starting
08-20-2014 08:53 AM