Computer - Inspiron 1520, Windows XP SP2 (more info at bottom of post)

Although I can play a DVD in Dell Media Direct OK (but with some playback problems, described in a separate post), when I try to play a DVD in Windows Media Player, I get the error message:

"The DVD key exchange for copy protection has failed. Playback is not possible."

I get a similar message in RealAudio:

"DVD cannot be played. Key Exchange for DVD Copy Protection Failed."


I found a Microsoft article that addresses this problem:

http://support.microsoft.com/kb/814846

But the solutions - update to XP service pack 2, and to DirectX 9.0c do not apply as those updates are already installed.

I tried Windows XP decoder checkup utility, but it confirmed that I had at lease one working decoder, so Windows Media should work.

So what else can I try to get media programs other than Dell Media Direct to play a DVD?


Additional system information:
2Gb RAM/Shared video memory
video adapter = Intel 965 Express Family
set to 1680 x 1050 true color (60 MHz)
video drive just updated - v. 6.14.10.4885
DirectX version 9.0c
Pioneer DVD +- RW DR-K17Y
Dell Media Direct v.3.3.3014
Hardware Acceleration is set to Full
Enable Write Combining is enabled
IDE ATA/ATAPI controllers - Transfer Mode set to DMA


Thanks for any advice