The customer preview program is closed, so Microsoft is no longer taking new
orders. In other words, you cannot order the DVD anymore, and while you can
still download Vista, you have to have a product key to install with. (And
Microsoft is no longer giving out product keys either.) The only reason the
download is still open is for people that already have a "genuine" product
key but haven't downloaded Vista. Sorry, but you're probably out of luck...
At least for now...