How to Install and Run Windows 8 From a Virtual Hard Drive

Traditionally, you would have to install different operating systems to separate partitions on your hard drive if you boot multiple OS platforms. The disadvantage is that malwares and viruses can spread among different partitions.
Another disadvantage is that it takes a considerable amount of time to create, delete or merge partitions when you need to. Since the advent of Windows 7, Microsoft has offered a new way to easily install and boot Windows from a Virtual Hard Disk (.vhd) file. This feature is even better in Windows 8.
What is a VHD file you ask? It’s a file format that emulates a real physical hard drive. It’s a hard drive within a hard drive—inception! In fact, you can even create and mount virtual hard drives within Windows 7 or 8 running from a VHD. I have yet to try an OS within an OS that runs from a virtual hard drive, but it’s possible with virtualization software like Virtual Box.
One of the benefits of a VHD compared to a physical partition is that it is a portable format. You can easily back up or restore it. Another benefit is security protection. If your other operating systems on the same hard drive get infected with malware, your OS on a VHD file will be isolated from that infection.
There are some minor disadvantages with running an OS from a VHD. Performance decreases about 3 percent, and you will lose the Hibernation and Bitlocker features. Moreover, only Windows 8 Pro/Enterprise and Windows 7 Ultimate/Enterprise support VHD booting.
Let’s create a VHD file so that you can install Windows 8 to it. You can do this during the install process, but it’s easier to demonstrate it using the tools available on Windows 7; that is, assuming you are running Windows 7. Step-by-step instructions are just ahead. 
1. Click on the Start menu and type in Computer Management and run it.
2. Right-click on Disk Management and choose Create VHD.

3. The minimum recommended space for Windows 8 is 20 gigabytes, but you will need more than that to run Windows 8 efficiently. For tutorial purposes, I just use 20 GB.
Keep the Fixed size option selected, otherwise Windows will run into issues if its hard drive space changes. Save it to a location that you could easily recall later. I named and saved win8.vhd in the root of C: drive.

Have your Windows 8 install DVD ready or a Windows 8 USB flash drive if you made one from the Windows 8 ISO you downloaded from Microsoft’s website.
4. Now boot to your DVD or USB flash drive from the start up screen, using F12 key or whatever the default key your system uses.
Let the system do its thing and it’ll eventually reach the Windows 8 install screen. Follow the on-screen steps until you reach this screen where it asks you to choose Upgrade install or Custom install. Choose Custom install.

5. Next you’ll need to choose where to install your Windows 8. But wait, you won’t see the virtual hard drive on that list anywhere. It’s not enabled yet, so you will have to attach it first. Press SHIFT+F10 to open up a secret command box.

6. Now type in diskpart and press enter so we could select and attach the .vhd file.

7. Type in select vdisk file=c:win8.vhd and press enter. Make sure to type in the correct location of where you saved your vhd file.
8. After it successfully selected your vhd file, type in attach vdisk and press enter. Now close the box.

9. Click on the Refresh button and the list will be updated with the virtual drive.

10. Select your virtual hard drive and click Next. Now go feed your cat or check your text messages and come back in a bit and you should have Windows 8 installed. That’s it. You’ll notice that your system will boot into Windows 8 automatically, but you will have the option to choose which systems to log into.
If, after awhile, you decide that you don’t like Windows 8 anymore, all you have to do is boot back into Windows 7 and delete the win.vhd file. It’s that easy!
Do you have any other tips or tricks for installing Windows 8 on a virtual hard drive?