1. If you are using VISTA, the folder will be called
Limewire, NOT .Limewire
2. You will only see that folder if (a) you have previously opened LimeWire & made settings. (b) you have turned on Show All Hidden Files & Folders;
How to find LW Preferences folder in Vista (click on blue link).
If you're not using VISTA, then see
Point #2 & 3 in Fixes for Limewire (sample image included at bottom of page.)