When you install a new hard drive in your machine, or buy a new machine, disk space seems almost unlimited. You start installing new programs, editing documents, downloading MP3s and suddenly, there's no more space. Part of it is, obviously, all the large files you've stored on the system, but even that doesn't account for where all your storage has gone. Some hard drive investigation leads to the discovery that your disk is filled with duplicate files: the same dll installed by different programs, the same......