People do get confused when they see the LimeWire playlist within iTunes. Unfortunately, that's simply a playlist & the actual files are still within your LW download folder. So you need to manually add them to iTunes Music Library via the techniques in the link Remoc gave you. There's several methods you can use. IF you don't do that, then should you remove or delete the music files in the LW download folder, then they will disappear from iTunes too. Which is why they need to be added properly. But at least iTUnes has its own music library. WMP is simply a playlist player ... & should you move or remove any files from their locations, WMP also won't be able to play them. With iTunes, once the files are within its own library they are safe.