Hi and welcome to the Gigabyte UK Forum.
As far as I can see it should work fine. It doesn't need any spectacular build specs. The requirements are only:
Processor requirements: 2.2 GHz P4 or equivalent (minimum) required for displaying ATSC high definition TV. on your PC screen
Microsoft® Windows® 7, Windows Vista (any version), Windows XP Media Center Edition.
Windows 7 AQ certified and Windows Vista Premium certified*
Available PCIe X1 or X8 slot
Graphics with 64 MB memory (or greater)
Sound card
Maybe the card is faulty if it is not even being picked up by the system. The card is sitting right down into the slot I suppose? There isn't anything stopping it from going the full way down?