I have already shown you the classic method of dual booting Windows 8, here is how to use a virtual hard drive (VHD) to Dual Boot Windows 7 and 8 Without Partitioning. No Partitions required.
Creating The VHD
1. To create the VHD, go to a run window by pressing Win+R, and type diskmgmt.msc.
2. An MMC console will appear, and will get the Disk Management window.
3. Click on the action button in the menu bar, and select Create VHD.To create a new VHD
4. Now choose C: for location of the VHD file and set the size, should be no less than 20 GB. Choose a fixed size for best performance.
5. Windows will then create the VHD, the progress of this can be viewed on the bottom right in the Status Bar of the MMC snap-in.
6. Once the disk is created it will be in the list of partitions in the Disk Management console. You need to initialize the disk by clicking on it and selecting initialize.
7. Leave the partition style at MBR (Master Boot Record) and click ok.
8. Once the disk has been Initialized, right click on the black space and select “New Simple Volume”.
9. Now we have a new VHD file that is acting like a real hard drive.
10. Next you need to download this script from MSDN, and then move it to the root of the C: Drive.
11. Right-click on the file and select properties. In the general tab click the unblock button in the bottom right corner.
12. Now you will need to mount the Windows 8 .ISO file that you downloaded. If you don’t know how to mount an ISO file check out our guide. Once you have mounted the .ISO image proceed on installing windows 8 on a VHD.
Installing Windows 8 On The VHD
1. The first thing you need to do is open PowerShell as an administrator by opening Start Menu->Search for->Windows Powershell, right-clicking on the Windows PowerShell shortcut, and choosing Run as Administrator.
2. When PowerShell launches type “Set-ExecutionPolicy RemoteSigned”. To change the execution policy to allow you to run scripts. You will get a security notice just type “Y” and press enter to accept.
3. Now type “CD C:” to switch to the root of the drive.
4. Now type the following command into the shell window:
.Install-WindowsImage.ps1 –WIM D:SourcesInstall.wim –Apply –Index 1 –Destination F:
5. You should substitute the drive letter that comes after the –WIM for the drive of the mounted DVD image, and substitute the destination drive letter, in our case this is F:, for the VHD that we created in the beginning of the tutorial. Then press enter.
6. Once it has completed you will be notified.
7. Now click start->search for command prompt, then right click and run as Administrator when you open the command prompt type “bcdboot.exe F:Windows” (assuming that F: is the drive with Windows 8 on it).
That’s it enjoy dual boot without creating a partition.