Unlikely anyone has hacked your computer. Are you sure you don't just need to expand the drop down list in LW's library. Click the little triangle thing beside "Saved Files" or "Shared Files".
If that's not it try deleting the LW Pref. folder. Points 2.) and 3.) in this thread:
Fixes for Limewire when LW isn't operating as it should! This will erase your settings for LW so you may want to make a note of them.