Hi, I'm having serious issues with mpeg2 playback on my system (retail Vista
Home Premium x64, fully up-to-date.) I first noticed the problem when Media
Center was not playing the video portion of live TV (I was using a Hauppauge
PVR card, but swapped in an ATi Theater 550 to test.) Further testing shows
that anything using the default decoders (i.e. Windows Media Player) fails to
play any mpeg2 file- I get audio, but no video. A lot of searching has led
me to believe that the problem was caused when I installed Nero 7 for a short
time. I've since uninstalled Nero, but I'm still having the same problem.
When I try to play an mpeg-2 file in Media Player and look at the file
properties, it tells me that it's using the "MainConcept MPEG Video Decoder."
I'm assuming this isn't the decoder provided by Microsoft.

Since Nero has been uninstalled, and there's nothing listed in "Programs and
Features" that looks like it would affect that decoder, can anyone tell me
how I might nuke this (obviously broken) decoder and go back to the
Microsoft-provided one? Media Center is all but useless to me without this
working.

Thanks,
Jim