VHD disk from physical computer not bootable

[nakeze]

Hello,
I try to virtualize a computer that runs windows 8.1. I used disk2vhd64.exe in order to create a VHD file of the C:/ and [no label] volumes on that disk. The virtual disk is stored on a SSD external drive.
I am using a windows 10 computer and virtualbox V7.0.8. I create a new virtual machine, enable the EFI mode, set the hard disk as first boot option.

The VHD file is still on the external drive, I don't have enough space on the computer.
I am able to set it as hard disk in the setup dialog box.

When I start the virtual machine, it is prompting error messages, boot not found.

Can someone help me to fix this issue ?

Sincerely

[mpack]

I used disk2vhd64.exe in order to create a VHD file of the C:/ and [no label] volumes on that disk.

Possibly I've misunderstood or you have worded it badly, but an image of one or more partitions (volumes) is not sufficient. You must image the entire drive, which (most importantly) includes the boot sector, partition map(s) and system partition (if GPT). The drive will not be bootable otherwise.

[nakeze]

Hello,
I am sorry I did not see your fast answer. I let this project hanging and resumed it yesterday.
Endeed, I was doing the copy badly.
I found my error with this thread on superuser forum:
questions/1070984/disktovhd-generated-vhd-is-not-bootable.

Long story short, with the EFI partition mounted, I am now able to virtualize all the needed partitions of the disk.