Sony handycam firewire free driver download windows 7

I have a Sony DV handycam which has fire wire connection to pc. My laptop with firewire connection was swiped, so I'm trying to get my pc set up (Windows 7 32 bit) to capture footage.
Purchased a Sunix fire 1394 wire card, installed only to find that there some serious interface problem fails to switch to capture mode, has text popping up saying "failure to build preview graph"
Have tried downloading all new versions of graphics drivers, still no luck.
Wondering if this is a case of obsolete hardware/ software issues.
Don't want to be forced to upgrade camera- works well.
Seems as though Sunix has been bought by Corel (sp?) and that I require a further purchase online- rather ridiculous, seeing I've just paid for a product that's supposed to function.

Any solutions?