Ahh, I see what you're asking now. I actually have the same Adaptec USB dual tuner conencted to the same PC that I use with the HD-PVR.
You won't be able to use the Adaptec tuner for anything more than a remote receiver as you will be configuring media center to use the DVB tuner (HD-PVR). I haven't researched being able to get Media Center to recognize both the HD-PVR as a tuner AND the Adaptec USB tuners so I can use them both at the same time. When I installed and set up the HD-PVR there was nothing there to set up the analog tuners.