Don't forget to use the forum search...you can look through old threads & maybe find an answer to your question.

Is LW connected (all green/blue connection bars)? If it's connected, try these fixes.

1. In LW go tools > options > searching > basic & check whether the 'show license warning' box is ticked. If it does, untick it > Apply > ok...see if that makes any difference.

2. Problems with the search

3. 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).
Fixes for LimeWire
This will change all of your settings within LW's options, you'll have to go back through afterwards & reset things to the way you like them.
Vista users: LimeWire Pref Folder in Vista

If LW isn't connected, you won't be able to search. In that case, try the fixes in the thread below & if nothing helps, post back with your system details.
If LW Will Not Connect