Answer:
There are several programs that allow you to copy DVD movies onto your computer so that you can watch them directly from the computer disc or hard drive. The best free ones are DVD Shrink, DVDFab, and DVD Decrypter. They are quite simple and straightforward. I would recommend DVD Decrypter if you are not sure about what you are doing.
On the Mac, a program called MacTheRipper works very well and is free (you can find it on versiontracker.com).

Removing copy protection from DVDs, or distributing ripped DVDs is illegal.

I use a DVD ripper which can rip DVD to video formats like avi, mp4,wmv,mov,flv,etc and convert DVD to audio files like mp3,aac, wma,m4a. you can download to have a try by clicking the related link for my answer.

Below are three free DVD ripper i ever used:
Handbrake (free. Google it)
DVD ripping software (free trial. You can get it from the link in the related links below)
DVD43 (free. Google it)
First answer by Sonert. Last edit by Aliasguy. Contributor trust: 0 [recommend contributor recommended]. Question popularity: 14 [recommend question].