Hi there natka,
I'm sorry to hear you're getting the error 777 here.
Can you tell me the OS your PC is running please? Also, if you could tell me whether it's just one modem (as you've stated yo have more) and whether it's critcal to one machine, or more than one machine.
Since you state that the modem works fine in another PC, then I'd lean towards there being a problem with the machine rather than the modem/SIM.
This link to
Microsoft's website may provide you with some assistance. It seems the error occurs when the OS has been upgraded, is this the case for you?
If you could let me know the answers to the above questions, I'm sure we'll get to the bottom of this.
Cheers,
LeeH
eForum Team