Vista - Issues with dial up connection

I am having problems with my internet connections on my Toshiba laptop. I am running Vista Home Premium 64bit OS. This laptop has an internal modem and was connecting to my provider with no problem till it went out yesterday. The modem fails diagnostics and will not dial. I went and bought an Encore ENF656-USB-AGER usb modem. The modem will dial and initiate a handshake but will not connect. I am able to get an error 678 remote computer failed to respond error by dialing through networking. I have updated my drivers for this modem and it is supposed to be compatible with this version of window. I have tried contacting my provider and the modem manufacturer with no good coming of it. I tried the modem on a family member's xp system and it dials and connects with no issues. I have tried a new internet connection setup but nothing seems to help. Does anyone have any further suggestions?