Here’s a video tutorial that shows you how to easily upgrade your HBOOT to Jelly Bean HBOOT 1.39 for your international HTC One X Android smartphone.
Why do you need this?
Well, if you bought the phone with ICS and never upgraded to official Jelly Bean (mine hasn’t), you will not be able to install the latest Jelly Bean custom Sense ROMs.
But by upgrading you will be able to install the latest Jelly Bean Sense-based ROMs.
Once done upgrading HBOOT, you will have a LOCKED BOOTLOADER, simply