|Is the cd rom a dvd rom drive as well ,and what program are you using to run the dvd.|
Google free dvd player....as you need software to run a dvd disk.
Not much to gone one from your post so I am thinking this is the first time you have tried to run a dvd.
To play a dvd you need both a cd/dvd rom and a program to run it. Windows xp does not have the built in software.