SymptomsWhile trying to play DVD in WIndows Media player of your Windows Virtual Machine, you see the following error message:
Windows Media Player cannot play this DVD because there is a problem with digital copy protection between your DVD drive, decoder, and video card. Try installing an updated driver for your video card.
CauseThe above mentioned error message pops up if you are trying to play a commercial DRM-protected DVD video. It means the content is copyright protected, because DVD manufacturers have adopted new anti-piracy codes.
If you are using a standard player attached to your TV or native Apple drive, the disk plays just fine, but in the virtual machine it is not played.
Your Windows Virtual machine has no its own CD/DVD drive, it uses your Mac emulated drive, therefore DRM technology cannot verify if it is copy or not.
WorkaroundYou might get your DRM-protected media played with help of third-party software such as PowerDVD or AnyDVD software but this is not guaranteed.
You may learn more about DRM technology here.