Windows 7 and booting a virtual hard drive

Having isolated environments for doing development, testing or just trying out new stuff, is extremely valuable. I for one have several environments, one for each client I work for, and a couple for working with internal projects.

In the early stone age we had to make do with multiple computers to achieve such isolated environments. Then came the advent of emulators and virtual computers. For many years now we have had virtualization solutions that run virtualized computers, but with a performance cost in both resource consumption and processing speed. Mind you, the performance keeps improving with better hardware support.

With Windows 7 however, a hybrid solution is introduced. By virtualizing only the disk subsystem, Windows 7 is able to boot from a file system that is completely contained within a Virtual Hard Drive file, or VHD. The end result is that OS and applications execute on “the bare metal” while a thin virtualization layer redirects disk IO to the VHD file residing on the bare-metal disk.

Guest author Thomas Sandberg gives a quick rundown on how to set up booting from Virtual Hard Drives with Windows 7. Read the article here!