ok now, congrats are in order! and you did fine, but didn't you say that windows popped up a message saying the new hardware may not work properly?
Although it seems to be working and all that you need to go to the manufacturer's site of that firewire card and download their drivers. What XP did was just installed a Generic version. They will work but you will not get full benefits of the installed hardware.
At the website....look dor tech support>downloads or just downloads and somewhere you will be asked to match the model number of your hardware and then you will get a download link or the likes. I always download as saved to the desktop. Then from the desktop I will either create a new folder and place it where evere it should go, or just open the file and it is self extracting and will load itself in the correct place.
You must then go into the device manager and locate the new card (1394, IEEEE ) and then highlight it and select properties and then press update the drivers and it will reinstall the new driver files. Either that are you need to uninstall the drivers in which it will uninstall the new card and then reboot as windows comes back up it will find the new hardware and then install the correct new drivers. That is how the system works... and no one is going to laugh at you for not understanding.