In playing an MPEG2 video in Window Media Player 9, if you go to File > Properties, it will tell you what MPEG2 decoder is being used. Now, I have installed several applications that come with their own MPEG2 decoder (MainConcept, InterVideo, Elecard, etc.) and it seems whichever one is installed most recently is the one that Windows Media Player decides to use. This leads me to believe that there is a registry key somewhere that dictates which MPEG2 decoder WMP uses. But I have been unsuccessful in locating that key.

I would like to know if there is a way to specify which MPEG2 decoder is being used, because some definitely work better than others and I don't necessarily want the most-recently-installed one to be the one WMP uses. For now my strategy has been to go locate the *.ax files of all the MPEG2 decoders that I don't want WMP to use and rename them to *.ax.old, so that WMP will be forced to use the one remaining MPEG2 decoder. But obviously this strategy is not ideal.

Any help would be greatly appreciated. Thanks!