Hard Disk Image not Opening

[epiphany]

Hi. I'm a complete newcomer to virtualisation, so please forgive if I've missed something obvious or some major prerequisite, but I seem to have fallen at the first hurdle!

I've installed v 5.0.8 host to Windows 10 64 bit PC, no problems. I have a Windows 98 hard disk from an old PC from which I've created an image file using disk2vhd, again no problems there. I try to open said image by creating a new virtual machine with 512MB ram then get the following error....


Failed to open the disk image file C:\Users\Peter\Downloads\Disk2vhd\SandEng.VHDX.

Could not open the medium 'C:\Users\Peter\Downloads\Disk2vhd\SandEng.VHDX'.

VD: error VERR_NOT_SUPPORTED opening image file 'C:\Users\Peter\Downloads\Disk2vhd\SandEng.VHDX' (VERR_NOT_SUPPORTED).

Result Code: E_FAIL (0x80004005)
Component: MediumWrap
Interface: IMedium {4afe423b-43e0-e9d0-82e8-ceb307940dda}
Callee: IVirtualBox {0169423f-46b4-cde9-91af-1e9d5b6cd945}
Callee RC: VBOX_E_OBJECT_NOT_FOUND (0x80BB0001)

[mpack]

VHDX is not a supported format, so you need to convert the file to a supported format first. Or, just don't select VHDX in the first place in Disk2VHD.

VHDX is very different from VHD, which VirtualBox does support.