Browser quit and won't work even though PC says I am connected, what is up?

HELP!!! Tech heads I need help. My cable Internet got upgraded. My old modem didn’t seem to handle it well as it would not produce an IP address so it would not connect to the model and/or the outer. I took the router off line and out of the loop for the time being. I upgraded the modem and was able to get an IP address. The problem is even though My Network Connections (OS WIN XP Pro w/Srv pack 3) says I am connected and shows me an IP address same as going to the command line and typing in ipconfig anything that has to do with the Web cannot get in or out, no Web pages, ICQ, Yahoo Messenger, etc. Have you or anyone you know ever had that problem? What would make Win see the router but not allow traffic to go back and forth?

Things that has been tried and failed:
• Made sure the browser was not on “work offline”
• Use of the Internet Connect Wizard
• Made sure the setting under Services was enabled esp DHCP.
• Tech support through the cable company.
• All connections checked.
• “Auto Detect Connection” checked in Int. Options.

I have done about everything I can think to get traffic going an nothing has worked, I am stumped. Time to go to the Jellies, give me what you got, what idea do you have?