Follow the more entailed instructions here Connection problems? Check here first! (click on link). The issue may be your softw firewall, but it might also be your modem/router. Make sure UPnP is enabled on your connection device. Instructions on above link.

If after doing this you still have problems, please post back the following details:

1. OS version? (eg: Windows 98)
2. What firewalls you have?
3. How much ram?
4. Hard Disk space available?
5. Connection type? (eg: dialup, broadband, cable, etc.)
6. Modem & router brand name & model numbers?
7. Where are you trying to connect from (home, school, work, etc.)?
8. What version of Limewire (LW) & Java do you have? (Go to LW's menu Help>About LW...) Will show both LW & Java version.
9. Who is your isp provider (Internet Service Provider)?
10. Are you sharing the connection with other computers or p2p sharing programs? If yes, please give details of set up.
11. Do this test again after setting your modem/router: http://www3.limewire.com:6346/