Try the TV card manufacturer's website but if it's considerably old it may not be supported on Windows 7, in which case best to buy a new one, I don't think Inno3D make TV cards any more: www.inno3d.com/
Couldn't find any on their website, not even in their Legacy section. Popularity of TV tuner cards has fallen dramatically in the last decade now that superfast broadband is here & you can watch internet TV without buffering glitches.