Many friends complain that:”I copied the DVD files in my computer, why I still can’t play it?”
The answer is simple, it is because most DVDs are encrypted with CSS copy protection. Decryption keys are often stored in a normally inaccessible lead-in area of the DVD disc. If you try to copy the contents of an encrypted DVD to a hard disc, you’ll usually get an error. However, if you use a DVD player software to play the movie it will allowing you to copy without error, but the encryption keys will not be copied. If you try to play the copied VOB files, the decoder will request the keys from the DVD-ROM drive and will fail. You may get the message “Cannot play copy-protected files”.
How ever, with professinal DVD copy/clone software – CloneDVD 5, you’ll be able to play it. CloneDVD 5 can remove CSS, RC, RCE, UOPs, ARccOS protections automatically, you can copy DVD to ISO, AVI, ASF, iPod, PSP, 3GP formats, etc.
CloneDVD download: http://www.clonedvd.net/