Assuming you are connected to the Internet first. Start Limewire and if it comes up with an error inside Limewire, go look in your Firewall for "blocked sites or applications" and if you find Limewire there look for the way that the Firewall allows you to unblock the site/application. If the Firewall is a 3rd part one e.g. work, they probably have a policy not to allow "peer to peer" networking and you will not be able to connect to Limewire.
Russell Taylor, December 2007