Nowadays, PCs are sold with either a DVD-ROM drive, or a CD-R drive. There are drives that do both, there are even drives that burn both. Either way, those of you with DVD-ROM drives will want to know if you can play DVD movies on your XP machine. XP out of the box won't play DVD Video. DVD's video is stored in a format called "MPEG 2", and you need an MPEG decoder to get the video off the DVD into a format that the computer can show you.
Without yet installing any third-party applications, I popped in my DVD of Fantasia 2000. XP asked me which application I wanted to open the disc with and I selected "Windows Media Player" since it was the only option - the other one being "Do Nothing". When WMP started I got a message box saying "WMP cannot play DVDs because there is no DVD decoder".
As a registered user of PowerDVD 3.0, I installed it on my XP machine. After reboot, I got an error about a missing ASPI file, but ignored it. I rebooted again and the message didn't come up a second time. Update Oct. 16, 2001: After installing PowerDVD 3 under the retail version of Windows XP Pro, this message no longer shows up. The error happened under Win XP Home Edition RC2. I started Power DVD 3.0 and without any hassle, Fantasia 2000 was playing on my PC.
I don't know the exact reason why Microsoft chose not to include DVD decoding in their XP operating system, especially since Apple includes DVD decoding in MacOS 9 and the soon to be released MacOS 10.1.
Update: Microsoft announced MP3 and DVD support via third-party add-on packs, available on Oct. 25, 2001
Subject: Windows XP and DVD 
Wed Mar 31, 2010 3:41 am