Control-alt-del & bring up the manager & make sure Limewire is not listed. If it is, force it to quit.
Now, delete your LW preferences folder; instructions here:
Point #2 & 3 in Fixes for Limewire (sample image included at bottom of page.)
Try installing again. If still problems, download the "Offline" installer (not the recommended one) from here
http://www.limewire.com/english/content/download.shtml