Later today, Microsoft will release Windows 8.1 preview at its BUILD conference in San Francisco. While Microsoft has yet to put up the download, here’s the link that you will need to get your hands on the build.
The download is not currently live at this time but should go up later today.
Steve Ballmer alluded to a different link but that’s not distributing the ISO’s yet.
Windows 8.1 will bring many new features to the platform including the option to boot directly to the desktop and the start button will return as well.