I have seen loads of webpages on how to run Windows on a VM in Linux, and how to run Linux in a VHD from Windows, but does anybody know how to do it (if possible) the other way round i.e. have linux as the main OS, but install Windows in a VHD (not a VM) in Linux?
Are you talking about native boot ?
Windows can not access a VHD in a Linux Ext3/Ext4 partition
You would need the system partition (FAT32 or NTFS depending if you have UEFI or not) and VHD on NTFS. You don't need Windows installed.
Boot to VHD (Native Boot): Add a Virtual Hard Disk to the Boot Menu
You need some way of installing windows in the VHD. If you aren't using Windows I guess you'd have to boot into PE and then you could install it using DSIM.
I don't know about grub I'm afraid. I use rEFInd as bootloader and it finds any bootable Windows (i.e. system partition) automatically.
Is your windows Installation UEFI or not ?
On my system (UEFI), I have
* Normal Windows 10 (ntfs)
* Windows 10 on VHDX (ntfs)
* Ubuntu on a dedicated partition (ext4)
on the same physical hard disk
I am able to boot either with grub or Windows to get use Linux or Windows :)
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