When you try to uninstall the current version of limewire are you doing it from Start > All Programs > Limewire > Uninstall ???
That is the correct way....
If you're doing it via Add/Remove programs then that can cause problems!!
Use your computer's search to look for all files & folders with limewire in the name. If you can't delete them, reboot into safe mode & then try. If they still won't delete, try one of the tools here...
Incomplete Download File won't delete at all.