Just for grins, I hooked up my "Mac-only" USB tuner card (an EyeTV Hybrid USB) and hooked it up to my Windows 7 machine. Much to my surprise it was recognized as a Hauppauge WinTV HVR-980 and I was then able to watch live TV and record with it. It has an ATSC tuner, but TV reception is very poor in my area so I'm simply using it with analog cable.
The problem is that the quality is barely acceptable. The image is grainy, titles often have streaks, and I'm seeing some interlace "artifacts". I can adjust some settings with WinTV (Hauppauge tuner software) but each time I reboot I have to change things back. This improves image quality some, but is still pretty poor. I've looked in device manager to change the tuner defaults, but nothing is available there.
On the Mac the image quality was pretty good for an analog signal. I'm hoping I can get close to it on my Windows 7 machine since I ditched my OS X box. Is there anywhere I can go to fine tune Window Media Center settings or defaults?