fully won't fully connect

I am recieving an error message that limewire is unable to connect to its host on the Gnutella network. This is most often due to firewalls or content-filtering software blocking access to Gnutella (port 6346). Please review your firewall's options to allow Limewire to access the Gnutella network or speak to your system administrator or ISP to determine if Gnutella traffic is being filtered. I am running Windows 2000 and have connection thru cable/DSL cox internet. ?# 1) How can I check my PC's firewall? #2) or check if the traffic is being filtered? Do you have an answer to solve my delema? Please!! This message appears even though I am fully connected to the internet.