Internet connecton problem.

Hi guys.
I have a cable internet about 128 kbs. I have a problem. To connect to the internet, i first have to connect my Local area network. But after Local area network's connection is established i get a message saying "Limited or no connectivity" and after this my pages appear really slowly and after sometime the pages stop to appear. What is the problem, is it due to firewall?
PLZ help

when you reeceive a message that says "limited or no connectivity" it means that you are receiving an invalid IP address ... that's the reason why you cant access the internet .. firewall could be 1 of the reason .. because some firewall blocks the connection from the computer to the Access Point or Router ... to solve this problem you need to release & renew the Ip address of your pc .. there are 2 ways on how to do that by restarting your pc & by going to ms dos prompt & type there: ipconfig/release then enter then ipconfig/renew then enter .. if still same ip add try assigning a static ip address in your pc ...