Dongle problem solved !!!
 

Thanks to Manole for the quick reply but I find the solution to my problem.

1st problem : When i try to connect the dongle it said 'dongle not find' approximativly 15 second after lauching usb-maintenance
Solution : it was due to the contact between the simcard in the dongle and the contactors.

2nd problem : When i try tio update the dongle it stops at 11% (or 18 % or 33%)
Solution : uninstall Activesynch (if installed) plug the dongle in other usb hub or in ufs hub and try and try and try ...

and the hangs problem occures to me many times i use the maintainance sw, what solution ?