[bettywnieves]

Anyone interested in protecting their own disks should not be particularly concerned. Copy protection, in general, does not work. If you have a self-written application, such as a toy or a CAD package, you might be interested in one of the commercially licensed schemes, using an electronic dongle. In general, however, if the disk can be read, its contents can be copied. If you don't want your data to be copied by anyone, you'd better encrypt it.
A simple and common way is to increase the length of several files on a CD to make them appear to be hundreds of megabytes long. This is done by setting the file length in the disc image much longer than it actually is. The file is practically overlapping many other files. Since the program knows the actual file length, the software will work fine. If the user tries to copy the files to the hard disk, the attempt will fail because the CD supposedly contains several GB of data. (In practice, this does not stop anyone because they always make copies of the disk image. Furthermore, no standard software allows you to create such disks.)