Have you tried opening the folder on your desktop & then copying the files within & pasting them into a different folder (rather than trying to move the whole folder from your desktop)?

Also, try shutting down LW completely (check in Task Manager, if a LW process is running then end the process) before trying to move any of the files from within that shared folder?

Check the thread below for more info about ways to add files to iTunes.
How to transfer music to my iPod (& iTunes)