nLite is a program that allows you to completely customize a Windows 2000 or XP installation disc (you can use
vLite for Vista. Basically, you can integrate upgrades or service packs, remove components, customize settings, and add or subtract stuff directly from the disc using the program. Once you're done editing, it makes an iso that you can burn to a CD and use to install.
I discovered just how amazing this program is when I was (for no reason whatsoever) trying to remove IE from my virtual XP installation. Not only did it allow me to remove IE (and add a Firefox installer to the disc), but I was able to slim down the installation disc from 650 MB to 250 MB by removing a lot of other useless stuff, and shaved my XP boot time (to working desktop) from 45ish seconds down to about 5 (not exaggerating). I always seem to make the coolest discoveries just by screwing around.
By the way, this process is completely legal (as far as I know), as long as you have a legally purchased install disc and product key, and you don't share the new disc with anyone.
Also, if you do this, do it on a test installation first, and don't blame me if you botch it. Obviously, a fair amount of technical expertise is required for this endeavor.