It's very easy to do, I have over 100 DVD's stored on my hard drive that I can watch using Media Center. To start, go get AnyDVD and install it on the machine you will rip the DVD's on (it removes the security on the DVD). The second thing you need to do is search for Vista Gallery Mode Hack on Google. Follow the instructions to change 1 regsitry setting allowing Media Center to emulate having a DVD Changer installed. Next, copy your movies to the Video's folder on the machine that has Media Center installed. Once completed launch Media Center, choose DVD Gallery, and then click on the movie you want to view. - If you want to add the DVD cover go to amazon, download the cover art into the folder on your machine that stores the TS_Video & TS_Audio folders. Change the name of the picture to folder - now the DVD Cover will dispay in Media Center. If you want the DVD movie information go to dvdxml.com and download the xml file for the movie. Save it in the same folder as the dvd cover art.
