30GB Fresh install

So today a bought a new 128GB SSD and installed windows 7 ultimate on it(Legit copy from the disk). Afterwards when I went into computer I was shocked to see the drive was already 20% full and I hadn't even installed drivers and such yet. This has never happened any other time so I selected everything on the disk to find that it took up 10 GB yet the disk supposedly has 30GB's of files on it. any ideas?

Most of the space is pagefile (the same amount of space as you have ram is eaten up if you have 8gbs of ram thats 8gbs of space) then there is hibernation space allacated ect ect.

Have a read of this gide for ssd's and how to get the most space ect out of it.