Quick question...
WHY WOULD YOU BUY SOFTWARE THAT YOUR OS DOES NOT SUPPORT!?
There's really nothing you can do except return the card and buy another one like a Dazzle. Dazzle comes with free software that works on most Operating Systems.
EDIT: Actually scratch that. If you can't figure out how to use an easy cap, there's no way in forget you'll figure out how to set up a Dazzle. :/