In Windows 7 and Windows Server 2008 R2, you can native boot from a virtual hard disk without a hypervisor In response to my posts about managing multiboot with Windows 7 and Linux, Microsoft IT Pro Evangelist Keith Combs sent me this e-mail:I just read your article and wanted to give you a heads up on an interesting new feature called “Boot from VHD” in Windows 7 and Windows Server 2008 R2. See a demo here. I stopped trying to run the various OSes in different partitions long ago when virtualization became viable. With boot from VHD, the performance gets even better.I was impressed by the video demo. To play with this capability yourself, you need to have Windows 7 or Windows Server 2008 installed already, and you need to download the Windows 7 AIK, burn the ISO to a DVD, and install from DVD. I’m not sure why you can’t use Virtual CloneDrive or the like to mount the ISO as a virtual DVD; perhaps they don’t yet run on Windows 7. The WAIK beta is downloading in the background as I write this.According to the WAIK documentation, which can be downloaded separately: In Windows 7, a virtual hard disk can be used as the running operating system on designated hardware without any other parent operating system, virtual machine, or hypervisor. Windows 7 disk-management tools, the DiskPart tool, and the Disk Management Microsoft® Management Console (Diskmgmt.msc) can be used to create a VHD file. A Windows 7 image (.wim) file can be deployed to the VHD and the .vhd file can be copied to multiple systems. The Windows 7 boot manager can be configured to boot directly into the VHD. The .vhd file can also be connected to a virtual machine for use with the Hyper-V Role in Windows Server® 2008 R2. Native-boot VHD files are not designed or intended to replace full image deployment on all client or server systems. Enterprise environments already managing and using .vhd files for virtual machine deployment will get the most benefit from the native-boot VHD capabilities. Using the .vhd file as a common image container format for virtual machines and designated hardware simplifies image management and deployment in an enterprise environment.As I understand it, the VHD cannot be on the Windows 7 boot partition, but you can have many VHDs sharing a partition. Another restriction is that the VHD cannot be on a dynamic partition. If you use a dynamic VHD (recommended for development, but not production) the underlying partition will need to have enough space to allow the VHD to expand. Software Development