Does it appear in Device Manager as an unknown device?
If it's not an unknown device, there's a chance Windows 7 has already recognized it. In this case you won't need to install a driver. You'll just need a TV software to use it, e.g. Windows Media Center, or ChrisTV, or some other.
If it's an unknown device, you could give a try to the Vista driver available from here (the "Yes" word is a download link):http://cdn.pinnaclesys.com/SupportFiles/PCTV%20Drivers/ReadmePCTV.htm