There's no network maintenance & no central server...you connect to other computers.
Try deleting LW's preferences folder when LW's closed. See points 2 & 3 below for instructions. If you've been using LW for a long time, you might have a prefs folder in either location.
It's not too difficult...please don't cry Fixes for LimeWire
If that's no help...post your details.
System details - help us to help you