how do i download update for my modem

I am really having problems staying connected to my server , and when i get connected it disconnects all the time this has been happening over a period of three weeks no iam continously on the phone to support . we have added so many strings i cantcount them anymore. they work for a while and they i have to put something else in please help my system win 98 se i have plenty of ram and should not be having this problem