If your budget is $1000, what is stopping from buying a new laptop? I recently purchased a Compaq laptop at Futureshop during a winter sale at $799CAD ($910CAD after taxes) and it works great! It has a 120GB HD, which is fine for everyday use storage, and for my multimedia I have a portable 250GB HD.

Something else you can try is either eBay for parts and for the OS

If you're really into Windows, you can buy it at a OEM price, just ensure you buy it at the same time as your hardware. But like many people said here, big chain dealers like Dell and such paid a distributor fee that allows to sell boxes with Windows for cheap.