The Problem:-

The DVD won’t run, giving me the following error message:Windows Media Player cannot play the DVD because the disc prohibits playback in your region of the world. You must obtain a disc that is intended for your geographic region.Resolution:- Drive Region Info is an utility to examine whether your DVD drive is region protected or not. When you have just bought a new drive, it is most likely region protected and you can change the region code only 5 times. Using the followng tool will help you to determine this.

http://www.remoteselector.com/driveinfo.htm

See also:-

http://www.mvps.org/marksxp/WindowsXP/dvd/regions/regions.php