Microsoft has released a new build, 5728-16387 of Windows Vista and Windows Longhorn Server to testers. The x86 and x64 builds are in English, German, and Japanese. In addition, the symbol files and tools were also released.Once you complete the download you must burn the ISO file to a DVD. If you don’t know if your DVD-burning software will support burning an ISO file, please refer to your DVD-burning software program and search Help for instructions on creating a disc from an ISO file. Additional instructions can be found on the Customer Preview Program website.
Before upgrading from Beta 2, please install any Critical Updates from Windows Update for Beta 2. Go to Start, All Programs, Windows Update, and click the “Check for Updates” button.
Windows Vista RC1 is available for participants of the Windows Vista Customer Preview Program. Please go to the Customer Preview Program website to register and receive a Product Key, which is required to install and activate the software."

Download: Windows Vista build 5728 | x64

MoreInfo: http://download.windowsvista.com/preview/rc1/en/download-5728.htm