Ok, ok. Here is a very weird problem I am having. Hope someone can help.

My PC is running on:

Pentium 4 3.0GHz
1GB RAM
Sapphire ATi x700Pro
Creative X-Fi XtremeMusic
External DVD Burner
Logitech Z-5500
Windows XP SP 2

Previously, I was unable to get any DVD-Videos (pirated or original, Region 1 or 3) to play on my PC.

I found out I required a DVD-Video codec, so I installed InterVideo DVD codec.

Then Windows Media Player was able to play the DVD, but no sound.

So I formatted the entire hard disk drive and reinstall Windows XP from scratch.

Windows Media PLayer still cannot play DVD-Video by itself, so I installed InterVideo DVD Codec again, and then also installed CyberLink PowerDVD.

Here's my situation now:

Windows Media Player can play DVD-Video, but in stereo sound.
CyberLink PowerDVD cannot play any DVD-Videos. It says Format Not Supported.
The only application that can play DVD-Video properly is VLC Media PLayer, running perfectly fine with Dolby Digital.

If you noticed, I am also using Creative X-Fi XtremeMusic sound card, which comes with it's own software known as Mediasource player. This application, together with PowerDVD, are able to decode DTS sound system. PowerDVD won't play, and Mediasource won't even recognize the DVD!

I have a sound card and speaker capable of producing great sounds, but the software that were supposed to support it do not work.

Can anybody help me out with this? Oh, I also re-installed the X-Fi driver and software. I am out of ideas!

Thanks for your help. Any help! HELP!

Thanks for all the replies.

As I have stated, I tried all types of DVDs, so Regions are not the problem here. Trust me on this.

Actually, almost as soon as I posted my problem (and sent an e-mail to Creative), I found out something great.

I had ASSUMED that VLC Media Player CANNOT play DTS tracks. I was WRONG!

I put in my DTS Demo DVD and played it with VLC Media PLayer. It worked! And the sound, oh the sound. The Gods will dance!

So my problem can be considered solved, since I can now play DTS tracks on my PC, but the inherent problem actually still persists.

Why can Windows Media PLayer decode only Dolby Stereo?
Why can't PowerDVD play any DVD-Videos?
Why can't my Mediasource even detect my DVD-Videos?

Let me try to get some screenshots so you guys can take a look at it.

And thanks for all your replies!