Anyone using WMC to share HD broadcasts on home network?

Just wondering if anyone has had success with Windows Media Center HD recordings of Clear QAM channels? I am using a legacy Vista installation with Windows Media Center. From research, Vista's default WMC does not record HD programming, only the analog broadcasts. I am wondering if it would be worth the expense of getting a Windows 7 or 8 system with a HDTV card just to get HDTV recordings as opposed to my analog recordings now. Anyone have a working PC system that does this? How are you enjoying it?

Follow-up topic to this... anyone have luck playing DVR-MS or .WTV files on set top boxes over the network? I think my research a few years ago indicated that the only Windows Media Center Extender on the marketplace are Xbox 360s. Currently, I watch DVR-MS files on my laptop over the home network. I have two set top boxes for network media streaming, but they can't play DVR-MS files.