Samsung Galaxy s3 4.3 update failing I am trying to update the firmware of my Galaxy S3 from 4.1.2 to 4.3. The update package gets downloded, but the installation fails at 31% everytime. I tried to updated using KIES also, but no success. What can be the reason and how can I resolve this issue?

The Error message is "Failed to update the firmware. Try again with Kies or contact Samsung".
Those of you who had tried OTA (over the air) or used KIES to update - and failed. My recommendation is FLASH your smartphone using software. I went to an authorised Samsung dealer who flashed my phone - and didn't have to backup either - and it took only 10 - 15 minutes, in total. Flashing uses proprietary software.