The information on many DVD's is encoded, almost solely for the purpose of making them difficult (or ideally impossible) to copy. Decryption software, (as it's name suggests), "decrypts" this information, so that you can extract it from the DVD, either to use on your computer, or to copy onto another. Most DVD burning software..(Nero, DVD shrink..etc.) has a built in decrypter, so that the decrypting is done automatically, saving you the trouble of doing it. The best DVD decription software available is DVD Decrypter (http://www.dvddecrypter.com)...and it's also free! (Of course you should make a donation to the author if you like the product). Most of the time however, the decryption on most burning applications works just fine, and you may never find yourself NEEDING to decrypt yourself. But for the rare instances you do, it's there. Using the software is remarkably easy. If you can burn a CD, you can use decrypter. It will save the information extracted onto your hard drive, where it can be viewed using any MPEG-2 compatable player, (WinDVD, PowerDVD..etc.). The decrypter does not, however, burn the information back to a DVD. You'll have to use some burning software for that. Note, that due to 60+ year old US congressmen (many of whom have never used a computer OR a DVD player), it is now illegal to decrypt the information on a DVD secured by commercial encryption..and yes, EVEN if you own a legitimate copy. See "The Digital Millenium Copyright Act". shaggy