I second this. I have no idea what to do specifically after downloading "Convert-WindowsImage.ps1".
Ok first off have to be in a Powershell prompt. Make sure you are in the same directory as the powershell script.
Then allow scripts....
Set-ExecutionPolicy unrestricted
Then here are some examples of course doctor them up to your needs.....Just copy an paste and then edit to your specific situation..... it does take some time to make the .vhdx like 7-8 minutes
PowerShell
.\Convert-WindowsImage.ps1 -ShowUI
Create a VHD using all default settings from D:\sources\install.wim.
PowerShell
.\Convert-WindowsImage.ps1 -SourcePath D:\sources\install.wim
# Since no edition is being specified, the command will succeed if there is only one image in the specified WIM file. If there are multiple images, the command will fail and it will list the possible editions.
Create a VHD using all default settings from D:\sources\install.wim while specifying an edition.
PowerShell
.\Convert-WindowsImage.ps1 -SourcePath D:\sources\install.wim -Edition Professional
Create a 60GB VHDX, using all default settings, from D:\Windows8RPx64.iso.
PowerShell
.\Convert-WindowsImage.ps1 -SourcePath D:\Windows8RPx64.iso -VHDFormat VHDX -SizeBytes 60GB
Create a 48TB VHDX from D:\WindowsRPx64.iso with a custom file name.
PowerShell
.\Convert-WindowsImage.ps1 -SourcePath D:\Windows8RPx64.iso -VHDFormat VHDX -SizeBytes 48TB -VHDPath .\MyCustomName.vhdx
Use WIM2VHD-style argument names to create a 20GB fixed VHDX with a custom name and an unattend file from D:\foo.wim, and return the path to the created VHDX on the pipeline.
PowerShell
.\Convert-WindowsImage.ps1 -WIM D:\foo.wim -Size 20GB -DiskType Fixed -VHDFormat VHDX -Unattend D:\myUnattend.xml -VHD D:\scratch\foo.vhdx -passthru
Enable serial debugging in the VHD, using COM2 at 19200bps.
PowerShell
"D:\foo.wim" | .\Convert-WindowsImage.ps1 -Edition Professional -EnableDebugger Serial -
Once you have a .vhdx follow this guide to make it dual boot....
http://bsmadhu.wordpress.com/2012/06/21/simple-way-to-try-new-windows-os-using-boot-to-vhd/