10.9. Playing DVD Movies
Windows XP lets you see the files and folders stored on a data DVD, which it treats just like any CD or hard drive folder. But Windows lets you open only files that it recognizes. And unfortunately , Windows XP doesn't recognize the most common file found on a DVD: a DVD movie.
That's because Microsoft left out one key component required to play DVD movies: a codec file. Short for COmpress DECompress, a codec contains the formula used to compress sound and video when stuffing them into a file, as well as decompressing them upon playback. Since Windows XP lacks DVD's essential "MPEG-2" codec, your movies stay locked onto the DVDat least initially.
To avoid fielding angry consumer phone calls, most PC manufacturers install third-party DVD software like "PowerDVD" when they sell a PC with a DVD drive. Once you or the PC's manufacturer install DVD player software, Windows Media Player sneaks over and borrows that program's codec, letting you watch DVD movies with Media Player, as well.
If your PC doesn't let you watch DVD movies, you have two options: