The problem is probably that you have a region 4 DVD and your DVD player is region 2 — see here.
You'll have to do one of the following:
Watch it on a computer's DVD drive, using a region-freeing program like , or indeed make a region-free backup (possible copyright infringement).
Download the free, open-souce VLC Media Player program: www.videolan.org/vlc. It ignores the region codes embedded in most commercial DVD releases.
Play it on a multi-region DVD player. Many standard DVD players are set to region 2 by default, but can be made region-free by typing in a series of numbers using the remote control menus. To find out if this applies to your own machine, do a Google search for "Your-make-and-model +region-free + hack".