That hardware don't work on Media Center. I tried that board in 2008 and eventually dropped it.
You have to use the software provided by ATI.
That hardware also has hardware defect. The HD Antenna input is prone to failure. ATI replaced my tuner 2x.
This ATI tuner started $149... Because it has a lot of HW and SW issues its now sold for $29.
I have been using Hauppage 2250.