Do you have to login with a user id and a password in order to access or connect to the internet service provider?
From the cable modem to your computer do you have a personal router in between? If yes you should setup your router to connect automatically to the ISP to grab the current leased ip either with static ip or dhcp.
Do you just connect it with Cat5 cable from the modem directly to your NIC card? In this case you will need pppoe set up to grab the leased ip.
What is your hardware setup?
Have fun :-)