Compatibility
In Windows 98 and Windows 2000, DVD Player only plays DVDs if a hardware-based MPEG decoder is present. In Windows Me, DVD Player supports software-based MPEG decoders.
With Windows XP, DVDPlay.exe was dropped as a separate application in favor of DVD functionality introduced into Windows Media Player. While the DVDPlay executable still resides in %Windir%system32, it simply executes Windows Media Player, but the Windows 2000 version can run on Windows XP/Vista/7 (with bugs). However, the full-working hardware-based version was still included with Windows XP pre-RC1.
Read more about this topic: DVD Player (Windows)