Link to VHD of Windows Vista from Microsoft Downloads.
For organizations with complex desktop infrastructures, whether large or small, Windows Vista Enterprise is the operating system designed specifically to help realize a better return on IT investments. In this VHD, you'll have the opportunity to road-test new and improved features including management (e.g. MUI, BDD, etc…) usability (e.g. Search, Navigation, etc…) and security (UAC, Windows Defender, etc…), enhancements to the Windows Vista platform.