First determine if the modem is operational. Go to My Computer/Control Panel/Modems.......and see if your external modem shows up there. If it does, click on the com port which indicates the modem is connected to highlight it and then click the "Diagnostics" tab to test the modem. Post back with results and someone can take you from there. If the modem DOESNT show up there......It isn't correctly installed.
Always wondered where Silicone Valley was...saw a pic of Pamela Anderson...now I know