vhdx – ramsgaard.me

I stumbled upon the concept of VHDX native boot. Its a rather old feature but very overlooked. When I had a windows laptop I would have loved this feature. Being able to multiboot so you could format your PC with still have the possibility to boot the old installation.

Its fairly simple, you OS is contained within a VHDX on your disk. The boot loader on the disk then has an entry of that VHDX file. Simple but yet powerful. You could have another VHDX for all your data and then a VHDX for OS. Then when booting into each of your environments you would have your data with you.

How to:

If you have a native os install today you can still use this feature. So it’s easy to convert into VHDX native boot. First, we need to do a bit of diskpart, then use dism to install the OS into the VHDX. But this can all be done while your old OS is running and you don’t have to prep USB keys etc.

Diskpart

We will create a new VHDX file with parameters of size and type.

diskpart
create vdisk file=C:\WindowsImages\w10ent64en-gb.vhdx maximum=51200 type=expandable
attach vdisk
create part primary
format quick label="System"
assign letter=W
exit

DISM:

Now we have a VHDX file that Is attached, formated, and has a drive letter. On to install of your OS. You will need your install media, for Windows 10 you normally use index 1, if you are installing Windows server index 1 is probably the server core install if you want GUI then install with index 2.

Afterward, bcdboot creates the boot entry into the boot loader and lastly, you can change the description on the entry in the boot loader, so that you can remember what has been installed.

dism /apply-image /imagefile:E:\sources\install.wim /index:1 /applydir:W:\
bcdboot W:\Windows
bcdedit /set {default} description "Windows 10 Ent EN-GB VHDX"

Conclusion:

You can now reboot and have the choice to boot your newly created VHDX with your fresh installed OS. So your company installed Windows laptop without admin rights, you can now boot into your private install so you have a company and private side of your work PC.