Windows 8 Release Preview Setup will check to see if your PC can run Windows 8 Release Preview and select the right download. Setup also features a compatibility report and upgrade assistance. Make sure your devices are connected to your PC and turned on before you run Setup. Built-in tools for creating an ISO or bootable flash drive are available for some previous versions of Windows (excluding Windows XP and earlier). You can find system requirements and additional information in the FAQ and in the links on this page.
Note before you download: Windows 8 Release Preview is prerelease software that may be substantially modified before it’s commercially released. Microsoft makes no warranties, express or implied, with respect to the information provided here. Some product features and functionality may require additional hardware or software.
For more details visit http://blogs.msdn.com/b/b8/archive/2012/05/31/delivering-the-windows-8-release-preview.aspx
Microsoft Press Pass http://www.microsoft.com/en-us/news/Press/2012/May12/05-31Windows8RPPR.aspx