I have a couple of thoughts on win7 x64 and mc7. I use a SiliconDust HDHomerun that works super on unencrypted QAM over cable. The default Quick TV feature provides a very nice and sharp picture via our 42″ Sharp LCD TV. However Quick TV is just a bit too simple with no guide or zoom features. I really wanted to use MC7 features for watching live TV. However the default MS codec in MC7 for TV (mpeg2?) provides a very poor image on SD stations. Zoomed images were even worse. Faces tended to loose all character and have a pancake effect. (Too much noise reduction? Too little sharpening?) Various attempts to add ffdshow to add the post processing had some side effects. Web research noted that no X64 replacement codec was available to replace the MS one due to DRM control. This is on live TV only, the main reason I wanted to use MC7. Well I bit the bullet and reinstalled win7 as X86. In The 32 bit MC7 the Live TV codec can be replaced with the Power DVD mpeg2 codec. That provides a TV image very superior to the MS codec TV.
Things I tried include tips from the HackMC7 people (that got me the Power DVD codec technique)
Installed Media Control from http://damienbt.free.fr/. That got me a functioning ffdshow in x64 MC7 with the MS codec but due to a (EVR?) bug the combination left me a green bar on the right side of the video.
So my current condition is MC7 for Live TV, recorded TV and a weather app.
Zoom Player with ffdshow for MVKs, AVIs and DVD playback.
I may try to add ffdshow and Media Control to the 32 bit MC7 if I get bored but no rush for now.