From the Norton help file.
<< Norton Protection, which shows on your desktop as the Norton Protected Recycle Bin, enhances the standard Windows Recycle Bin by protecting more files from permanent deletion. UnErase Wizard allows you to recover these protected files. >>
<< The Recycle Bin only protects files or folders deleted while you are using Windows. The Norton Protected Recycle Bin additionally protects files that are deleted while you are using DOS, files created and deleted behind the scenes by Windows applications, and older versions of files you modify and overwrite. If the Recycle Bin is not enabled, Norton Protection also protects all files that would otherwise be under Recycle Bin protection. >>