A: Did you configure your firewall so it allows LW full access (advisable not to have 2 active firewalls b/c they can interfere with each other); Firewall configuration instructions (click on link)

B: It may be the version of Java you're using. Sometimes one version doesn't seem very compatible on some people's systems compared to the other version. If you have version 1.4.2 then update it to 1.5. But if you have version 1.5 then uninstall it using your Add/Remove control programs control panel & then install 1.4.2 but use only the offline installer. See Fixes for Limewire

Can you give us a total desciption of your set up:
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?
10. Are you sharing the connection with other computers or p2p sharing programs? If yes, please give details of set up.
11. Is this a your 1st try at LW or is this a new problem with an experienced user.
12. Do this simple test for us. Using your browser go here: http://www3.limewire.com:6346/ The page should say 'Your test worked!'. What happens when you go there?
These details are vital if you want us to find out what your connection problem is.