Re-installing OS from the partition on a HP laptop

I just learned that the new laptops do not come with a restore disc from the manufacture. I am looking at purchasing a new laptop this one HP Pavilion dv6810us 15.4" Widescreen Notebook Computer With AMD Turion™ 64 X2 Mobile Technology TL-60

My question is if I need to re-install the OS Vista home in this case how do I do that re-install the os from the partition on the hardrive? I have always done it when I do a fresh install I format the entire drive at the beginning. Plus I do not like the fact that the OS and the partition is taking up to about 10GB of space.

What are some of my options?