Disable and Replace MS DTV/DVD Decoder
by Michael Healy @ 8:15 am on April 8th, 2009 in codecs, ffdshow, mkv matroska, windows media foundation with 59 Comments and Permalink
One of the problems people run into when using Windows 7 Media Center is that it’s locked into using Microsoft’s own decoder for live TV. Not only that but if you should try to simply disable this codec (because it’s also locked in for all h.264 content used in videos) live TV playback won’t function. This happens because codecs such as FFDShow aren’t able to handle the live TV stream coming from Windows 7 Media Center.
Want to Keep MS DTV/DVD for live TV playback? Use this guide, instead.
What we need to do is disable the Microsoft DTV/DVD Decoder so we can use FFDShow and the like for our movies then replace the codec used for TV playback with a suitable replacement. First, install the codecs you intend to use to playback video content other than live TV. If you’re in need of a guide on this try Playing MKVs for Minimalists on Windows 7.
Once you’ve got basic movie playback working we need to find a suitable replacement for live TV playback. This has very specific requirements including being able to work with DRM built into Windows 7 Media Center. One codec that has been found to work perfectly in this situation is the Cyberlink video decoder included in PowerDVD 9.
The easiest method to access the Cyberlink decoder, if you don’t already own Cyberlink PowerDVD 9, is to download the trial version. For those looking for a more minimalist install you can follow these steps to extract only the necessary decoder from the trial install package (taken from the MediaPortal Forums and modified for 7MC):
- Download PowerDVD trial software here.
- Rename "CyberLink.1501a(DVDTrial)_DVD081031-03.exe" to "CyberLink.1501a(DVDTrial)_DVD081031-03.zip"
- Open "PowerDVD9.1501D(Trial)_DVD081031-03.zip" in a program like 7zip
- Extract "[ data1 ]" and rename it "[ data 1 ].zip"
- Open "[ data 1].zip" in 7zip and Extract "data1.cab"
- Find "_A2999B32CFD14E0385CC0CC8DB803CB4" file and extract it on your "C:\" root
- rename "_A2999B32CFD14E0385CC0CC8DB803CB4" to "CLVsd.ax".
- Open an elevated command prompt (start > cmd > ctrl + shift + enter)
- Type "C:\Windows\system32\regsvr32 C:\CLVsd.ax" and hit enter
- You should receive a message stating the proccess succeeded, otherwise try the process again
*Cyberlink codecs are usable only in 32-bit installs as far as I know
Now to disable the built in Microsoft DTV/DVD Decoder. The simplest way to do this is to just rename the decoder in the system32 folder. Open Windows Explorer and navigate to “C:\Windows\system32\”. Find the file named “msmpeg2vdec.dll” and rename it “msmpeg2vdec.dll.bak”. This will disable that particular codec and may cause instability in other programs so this is recommended only for pure Media Center installs.
After the default Microsoft codec has been disabled we need to instruct Media Center to use the Cyberlink codec instead. To do this open regedit (start > regedit > ctrl + shift + enter) and navigate to:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Media Center\Decoder
Locate the entry labeled “PreferredMPEG2VideoDecoderCLSID” and double-click to modify the value. Enter “{3AC8EA8C-990A-424A-BD7B-D5B57A9DEB83}”, without the quotes as the new value. This is the CLSid of the Cyberlink Video/SP Decoder. You can double-check the CLSid using RadLight’s Filter Manager with this guide.
Not Already Subscribed to the Hack7MC RSS Feed? Why not join those in the loop on the latest hacks for Windows 7 Media Center and subscribe to the RSS Feed today!

