1. 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)
2. Try out some of these suggestions such as changing compatibility mode to win 2k, & if one version of java doesn't work, try another as listed here:
Fixes for Limewire Also try deleting the preferences folder as described in the link.
* Don't go for a really old version of LW! Not only will they have bugs but the newer programs on the gnutella network community block many of these older versions out from connecting. And some people will just ban those users. The older versions are not healthy for the Gnutella network. If you want to try a different version then try the beta 4.9.x
http://www.limewire.com/english/content/beta.shtml