Update 2.1 for Windows XP Drivers

I recently bought a 2009 iMac (24"/2.66GHz) and want to install Windows XP Pro SP2 via Bootcamp.

I imagine I'll update to XP3 once installed and noted that this update will be required. So I downloaded the 215MB WindowXP Drivers Update file from the Apple's Download site.

Here's where I'm confused. All I seem to have in my 'Downloads' folder is a 215MB file named BCUpdateXP.exe. When I click to open this file the TextEdit opens and there is a small window (I'm still learning apple lingo) that has a bunch of gooble-de-goop (I think that's the technical term).

How do I install this new driver file?

Thank you for any information.

You have to start Windows and install it there.

BJJackson is correct, the update must be performed from within Windows itself.

Thank you. I figured I was getting ahead of myself.

I'll wait 'til I install XP.