I am changing from an analog capture card (DC10plus) to a firewire card and DV format. I am using Video Factory 2c. Will Video Factory recognize the card or will I have to reinstall the software and register again with sonic foundry?
You should be able to re-install VideoFactory as often as you wish and not have to re-register. You only need to re-register if you re-install your O/S.
If your O/S recognizes the new firewire card and DV camcorder, then VF should also see it without having to re-install.
You shouldn't have to reinstall at all. The next time you start video capture it should list "Microsoft DV Camera" or something like that in the list of video devices. Choose that and you'll be all set.
VERY IMPORTANT ... if the firewire card comes with a driver disk, toss it in the garbage (the disk, not the card) and do not use it. Let Windows install the microsoft drivers for the card. It will do this quite easily and automatically (i think the process took about 8 seconds on my computer).