Cannot find Firewire connection for external Harddrive

I have an external enclosure which houses a new Hitachi 80 GB Harddrive.
When I use the USB output to the computer, it sees the Harddrive.

Yet, when I use the Firewire on the external drive and the computer, it does
not see it.

I do not know whether I should use the Control panel to add hardware for the
Firewire and if yes, what should I look for?

I have used different Firewire cables, same negative results.

This is with Windows XP and a 1.1 AMD, 512 MB RAM.