You should have used Wubi to install Ubuntu, it's ridiculously easy - just give it a username, password, and virtual hard disk sizes, and that's it

You don't even need to repartition or anything, I installed it on one of my work laptops like this on Monday
I personally prefer Gentoo myself too, but Ubuntu's great to install when you're feeling lazy and/or don't have the hours to compile everything from source
I'll also use this thread to recommend the PartedMagic linux CD - it allows repartitioning for dummies
from a bootable disk, and is way more slick and functional than Partition Magic
