Gentoo Linux would be a very good choice, but if you don't know much about Linux you might get lost quick. Try maybe an older distro of Linux, like Mandrake 6, or Redhat 7.2 Suse might be aviable option, but I don't have experience with it, so I don't know. Sorry, I'm a Linux boy. Windows is expensive and sluggish on even a 10 gajillion hertz CPU.....
Lot's of reading, but you might want to take a look at www.linux-on-laptops.com They even have some user forums which may provide the answer.