I have added a lot of music during the last year and when I finally went to add them to WACUP's library I saw two things missing from where I expected them. With Winamp, when you click "Library" you have the options to "Rescan watch folders..." and "Remove missing files...". Are those options somewhere else in WACUP? There are other ways to add new music but none that I know of to remove files that have been moved, deleted or renamed.