Can't get a signal to my computer

I have been using a little Webstar modem and just bought a Motorola SB4220 modem to replace it. I can't get it to work. I did not receive an installation CD with the modem. I am hooking it up with a coaxle cable to the modem from the wall and an ethernet cable from the modem to my computer. I am running windows xp. I downloaded drivers but it will still not work. Do I have to have the CD in order to get it to work.

Thank you,
Jerry Van ****
jvd0415@yahoo.com