Manual update won't install

I have a 4th generation Apple Ipod connected with firewire to my Windows
Vista computer. I found that when I had the Ipod connected to the computer
it would randomly reboot. Windows found that there was a patch for an
IEEE1394 issue in Windows Vista. After downloading the manual installer
(sorry the update number escapes me, and I am not home) and running it,
Windows says that my machine does not require this update, and then closes.
How can I force this update to install? I am logged in as an admin and have
full access to everything on the machine.

I know that I can connect the Ipod with USB but I would like to use my
Firewire and leave my USB port for flash drives and other quick use stuff.

Any help is appreciated,

Lars