TVersity, DirecTV and Windows 7

After upgrading my media computer to Windows 7, I found that my TVersity installation had more or less disappeared.  I reinstalled it and found that nothing (NOTHING) would play in my DirecTV HR21-100 MediaShare receivers.  Bummer.  After several hours of fiddling, here's what I found out.

1. The latest version of TVersity (1.9.2) appears to have problems with DirecTV, so I reinstalled version 1.8.
2. Much prowling around showed me that my codec installations had been broken, probably by the Window 7 upgrade, although I can't be sure.  I removed all the codec packs I could find and reinstalled TVersity, which reinstalled its codec pack.
3. The 1.8 version allowed me to play most of my AVI and M4V files without any change to the PROFILES.XML file or fiddling with access rights to the TVersity server or the folders containing my media.  That was good.
4. However, MP4 files would not play.  Upon investigation using GSpot (http://www.videohelp.com/tools/GSpot) I found that the MP4s used an H.264 codec which wasn't recognized.  Many people complained about the Microsoft-supplied MPEG4 and H.264 codecs.
5. I found a simple program called a "filter tweaker" (http://www.download.hr/download-filter-tweaker-for-windows-7.html) that let me see which codecs were available for H.264.  Interestingly, I did have an ffdshow-based codec for 64-bit H.264, but not one for 32-bit.
6. I installed a recent build of ffdshow (http://free-codecs.com/download/FFDShow.htm) and installed the 32-bit version.  After the obligatory reboot, I found that I now had an ffdshow alternative to the 32-bit Microsoft H.264 codec.  I selected that codec to be used.

After chosing the ffdshow 32-bit H.264 codec, everything seems to play just fine, even when setting my preferred video resolution to 1920x1980.  The lessons here are:

• Remove all codec packs BEFORE upgrading to Windows 7.
• Ignore 94.7% of the information about codecs, TVersity, DirecTV, etc. on the Internet: if the page entries date before 2009, they are serious out of date.
• Find a way to peek inside a video and determine its codec.  Most video files are mere containers for video interleave streams.
• Use one of the 'filter tweaker' programs to fiddle (recoverably) with your system's codec choices.
• Only install the absolute minimum needed to get everything to work.  Windows 7 is, in spite of all of the above, a far better video generation engine than Vista was.

Good luck!