Alright, try this: Delete LW's preferences folder when LW's properly closed. See point 3 here & also point 2 if you've used older versions of LW in the past (there could be a folder in either location). Don't forget to show hidden files & folders, so that you can see the folder within Application Data if it's there.
Fixes for LimeWire
This will kill all of your settings within options, you'll have to go back through afterwards & reset things. If you're not sure of your settings, go through LW's tools > options & write them all down, so that you can reset things later.

Are you downloading your LW installers from Lime Wire » Official Website & Free Download «
Has it ever worked in the past??