Seems that you have to clean out the complete LW installation before you can re-install it. You might have removed LW via the Control Panel>Remove Program function.
First, check whether there is a LW exe running in your Task Manager (press crlt&alt + delete one time to open it). If there is, force it to end.
Then look whether LW is still installed (START>Programs>Limewire). If it appears in the list use the Uninstall of that program list and uninstall it.
Now you go and search your computer for any remaining limewire folder (START>Search>Folder and Files.....type "limewire" as seach query). All folders you find you just delete.
Then open your registry (START>Run.........type " regedit ") and go to Edit>Search and type " limewire " as search query.
Delete all keys you find.
So, that should it be,.....restart the computer and try to re-install it. But make sure you have installed the latest Java downloadable from here:
http://java.sun.com/javase/downloads/index.jsp 