Have you configured your firewalls for LW:
http://www.limewire.com/english/content/firewalls.shtml
Try these one by one until one works:
1. Delete the LW Preferences folder called
.limewire (whilst LW is closed!) & found here: Windows NT 4.0 / 2000 / XP: C:/Documents And Settings/your_username/.limewire (BUT make a note of all your LW settings 1st b/c you'll need to reset them after deleting LW's Prefs folder!!!)
2. Update your Java
version 1.5 (take the JRE)
3. Repair LimeWire using the Add/Remove Programs utility. Go to Control Panel then Add/Remove Programs & click on Limewire on the Change/Remove button & it comes up with options and one of them is Repair. Try this.
4. Right-clicking the Limewire icon and going to properties and changed compatability setting to Windows 2000.
5. Right-click on the Limewire icon on the desktop and click on Run as. Then it should come up showing the current user and then switch it over to Administrator.