Why Windows 7 looks so much like Vista
But JayDog at TG Daily says there's a good reason for that: most of the changes are at the kernel level. He says Windows 7 Milestone 1 actually installs on top of Windows Vista SP1. You can't install the OS on a clean system. Once you install Windows 7, you will automatically have a dual boot system with the option of booting into either Vista or Windows 7.
JayDog reports that his system seems a bit faster when running Windows 7 than Vista, but as a user he really didn't notice any other differences. Of course, Windows 7 M1 isn't really intended for end users. It's for computer makers, developers, and other Microsoft partners who need to see how the new code affects their products. So while there may actually be leaked copies of Windows 7 floating around, we can semi-definitively say there's no real reason you should try to track down an installation disc. Not yet anyway.