You could try calling them and asking them for help. There is a decent chance that the entitlement to some support and possibly even a current license to software goes along with the hardware, so showing them some proof that you now own the card or dongle may entitle you to some advice and possibly even the software that came with it. Its worth trying. I have an ancient Hauppage card too and I vaguely remember doing that at some point. I was on Linux, I think, BTW. (This was at least ten years ago, though. In the pre-ATSC era.) Ask.
If you want to use it on Linux, LinuxTV.org has info on a lot of hardware variations, nothing on windows software, but on the hardware parts/chipsets, etc...
They are I think in Hauppage, NY. (US)