I have the Sonic Cineplayer DVD Decoder Pack v 2.31_SDD from Sonic Solutions. It has run perfectly for several years until the other day when I installed files for my new Blackberry. When I try to play a DVD on Windows Media Player, it comes up with this 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." People have mentioned that the Blackberry software has over written DLLs that Cineplayer can no longer use. Is there a way to recify the problem? Thank you.

SOURCE: problem loading sonic cineplayer 1.5 from disc

Don't use the auto download system. Go into My Computer and access file download directly on F Drive. This eliminated problem. J

SOURCE: DVDs will not play on drive(DRW-1608P3S)

The reason for this issue is the lack of a codec software like Cyberlink PowerDVD or PowerCinema.These are paid versions.We could try installing a codec pack from Klite.Its free.The link is : http://www.free-codecs.com/download_soft.php?d=5075&s=775 Please let me know whether it fixed it

SOURCE: Windows Media Player cannot play this DVD because there is a prob

uninstall all the decoders u have installed like, k lite and ffdshow. i solved my problem to this today. i also went to device manager in control panel and clicked on cd/dvd drivs and disabled the one that plays my dvds, in my case it was a blu ray drive, after u have disabled it by right clicking and pressing disable. i then restarted my computer and then when it had restarted went back to device manager and enabled the dvd drive that i had originally disabled and everything worked fine :D hope this helped. Adam

SOURCE: it used to play dvd's, but will not play anymore.

First confirm you have DVD decoding software on your machine (such as PowerDVD). You MUST have a dvd decoder for movies to play.
Second, have you been changing the region settings on your dvd player? The device (not just Windows) allows 5 changes, and once theyre used up, the device is permanently in the last change made, even if Windows is reinstalled.
Third, if you have a specialized video card with extra abilities (such as a TV tuner) the software and drivers for it may be missing. Head to Dells website and see if there are additional drivers for your notebook.
If you got the notebook from Dell and its still under warranty, they may be able to help you resolve. Good luck.

SOURCE: I have a Compaq Presario SR5502UK that won't play

Make sure your default player is not window media player, you need software like PowerDvd which is embedded with the mpeg2 encoder. An alternative software that is not as fancy but works well can be downloaded from the link below:
http://www.videolan.org/vlc/