I think your a little confused. Any files you d/loaded were saved to your hdd and four years ago, the default location would have been C:\Documents and Settings\"your account name"\shared.
LW doesn't keep track of the files you d/load. Also if you purchased the Pro version, your account has long since expired and your email address has been deleted from their data base.
Try searching for the files on your hdd. From your desktop go to, Start > Search > All files and folders, and search for mp3, or the name of a file you remember.
If they're no longer on your computer, you'll have to start over again
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