Try these things one by one until one works:
1. Update your Java
version 1.5 (take the JRE)
2. 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 OR Windows 98 / ME: Your .limewire folder is in "C:\My Documents" (BUT make a note of all your LW settings 1st, b/c after you delete the LW prefs folder you'll need to reset them.)
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.