Infoseed might be a good idea as they offer very good prices.
You'd be best off putting Ubuntu on it rather than Windows.
Don't buy a new computer, that's just a pointless waste. If you want something that comes with a warranty, you could buy a second-hand refurbished one from a shop (which is more expensive than the freegan or infoseed route, but much cheaper than buying a new one).
I've had it with you. If I had an image of a laser gun I would absolutely position it right here in my hand...
Ha! I have a real laser absolutely positioned in my hand!