Note that Inmarsat have found a potentially serious bug in the latest firmware (5.2.0; and also in 5.1.0).
They will release a new revision on Feb. 8.
See
http://isatphonelive.com/support in due course.
Before updating you should d/l and install the latest USB drivers for your 'puter. How to do that will be on your CD. From memory under Software, not manuals or doc.
This alone takes some time and effort. Follow the instructions to the letter. Install them all.