Playing DVD Video through Windows

Technological improvements over the past few years have allowed PCs to become a great alternative option for viewing high quality video. Computers designed specifically for this purpose are called HTPC(Home Theatre PCs). They are generally powerful enough to view video, and contains video cards which improve visual clarity and increased contrast. Newer video card ports allow high definition video from the PC to be connected to digital television through HDMI, DVI, or component inputs. For analog television, many video cards also come with S-Video and composite headers for connection to the TV. 

Here are a couple recommended DVD Players:

Windows Media Player 8 and above 
Microsoft has included upgradeable versions of Windows Media Player in Windows XP (currently up to 11), which can play many types of video and audio formats including DVD and VCDs. The latest versions can be obtained free through Windows Update. 

The Windows Media Center Edition operating system even contains a built in HTPC frontend with DVD viewing capability. Media Center is optimized for easy navigation using a supported Media Center remote, perfect for a HTPC setup.
 
VLC Media Player by VideoLan
VLC media player is a highly portable multimedia player for various audio and video formats (MPEG-1, MPEG-2, MPEG-4, DivX, mp3, ogg, ...) as well as DVDs, VCDs, and various streaming protocols. It can also be used as a server to stream in unicast or multicast in IPv4 or IPv6 on a high-bandwidth network.

VLC Media Player is another free alternative to Windows Media Player. VLC will decode a wide range of video formats with it's internal decoders with no need to install any additional codecs. 

For the latest version and more in depth information about this project, click here to visit the VideoLan website.
 

MPlayer 
MPlayer is another GNU General Public Licensed open source software project developed to play a great variety of video and audio types, including DVD video. MPlayer supports a broad range of video codecs, allowing strong adaptability for just about every popular media file format.

 
MPlayer's main development platform is Linux, but has since been ported many other operating systems, including Windows and Mac. MPlayer does not yet an official GUI for these operating systems, but it's lack of a visually appealing graphical interface is made up by it's powerful functionality and lower resource requirements. 

Update to date information about MPlayer can be found by clicking here.