How to transfer a clip from DVD to computer,tried but not working?

I have DVD,and I'm sure it isn't copyrighted or anything like that,because I easily got a clip off it and uploaded it to YouTube. However,it was not the clip I wanted. I am using a free version of "Videopad" and it helped me with the first clip,but it won't upload the one I want. Whenever I spend a long time trying to get the files onto it,it turns out it will only go onto Audio. I don't know why this is,and even resorted to my Webcam,which was bad quality. Is there any way I can upload this 16 minute clip? You can buy it online,but I can't because I'm on a shared computer.