You will have windows firewall right? Make sure LW is on the list of exceptions. Setting up an exception for LimeWire in your software firewall (click in link)

For those who updated their LW & then had connection problems, the problem is usually the gnutella.net file, but also possibly the advanced performance settings; check suggestions here If LW Will Not Connect (click on the blue link)

Otherwise, the problem might be your modem/router's NAT protection which has a similar effect as a firewall. We need to know which brand And model, which is why we always strongly ask people for their system details, we cannot help much without them (breathes out more easily now)
System details - help us to help you (click on blue link)