Can you describe what problems you're having precisely? Are you running the latest version of LW? You can check this by going to Help->about limewire. The latest version is 4.18.3.
Also, check firewall settings, limewire adds it automatically to the Windows Firewall, but other applications, notably Norton, can be problematic.
Check to see if you have any firewall SW and add LW as an exception. Also, make sure that your provider allows file sharing.
Good luck!