Hi doctot bob, you'll have to install a firewire card. This is dead easy - even I can do it. Turn off the PC, open up the case and drop the firewire card into a free PCI slot - you'll see where it goes. Screw it into place, put the case back on and boot up the PC. Windows should find the card and install the drivers without any hassle.
Dabs.com is a good place to buy a firewire card.