For Win XP:

Deleting the preferences folder will change all of your settings within LW's options (eg download & upload speeds, days to keep incomplete files, location of saved folder, keywords being filtered, listening port etc etc). If you're not sure of what your settings are, go tools > options & write things down before you delete the prefs folder

1. Go to Control Panel > folder options > view. Check the radio button to show hidden files & folders > apply > ok.

2. Shut down LW. Make sure it's completely closed by checking in Task Manager (ctrl/alt/del). If there's a LW process running, end the process.

3. Go to My Computer > C drive > Documents and Settings > your username. Look for a folder called .limewire (this is the old location of the prefs folder, so it may or may not exist depending on whether you've used older versions of LW in the past). If there's a folder named .limewire, delete it.

4. Go back to Documents and Settings\your username. Open the Application Data folder & look for a folder named LimeWire (no dot in front of it this time & the name's not all lower case). Delete that folder named LimeWire.

5. Restart LW & go to tools > options...reset the options back to the way you like them

There are screenshots & instructions in points 2 & 3 of this thread: Fixes for LimeWire

If you're using Vista, there's a few things that are slightly different...the thread below will help with that.
http://www.gnutellaforums.com/genera...der-vista.html