|Movies come on DVDs while videos can be burned on CDs. The most rudimentary question would be are you trying to use a DVD in a CD player? That wouldn't work.|
If the disc and drive type are in order, have you tried other discs and can confirm this single disc is the only problem? Does the disc have any visible scratches on it? Does the disc even show up in My Computer? What program(s) have you tried ripping the video with?
What Ewen and I are both trying to illustrate is that we need more information to help you. My list of questions is based on assumptions that may not even matter depending on the problem.
Apologies if I don't respond to your reply immediately. I don't check this site daily, but you're welcome to PM me as a reminder.