Boot image not found in Hyper-V

The important error in your screenshot is "The boot loader did not load an operating system." The PXE boot error is secondary because Hyper-V attempts to boot from the network after failing to boot from the virtual hard disk.

Since you created the VHDX using Disk2vhd, I suspect that the EFI System Partition was not captured correctly, or that its boot configuration is missing or invalid.

Your screenshot shows a Generation 2 Hyper-V virtual machine, which uses UEFI firmware. Was the original Windows installation also using UEFI/GPT?

I would first boot the VM from a Windows installation ISO, press Shift + F10 to open Command Prompt, and run:

diskpart
list disk
list volume
exit

Please post a screenshot of the results. This should help establish whether the VHDX contains a suitable EFI System Partition and whether the virtual machine's generation matches the original installation's boot configuration.

If the EFI partition is present, it may be possible to repair the boot configuration using BCDBoot without reinstalling Windows.

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1. Run Disk2vhd as Administrator.
2. Make sure to check the box for both the hidden System/EFI partition and the C: volume.
3. Create the new .vhdx and attach it to your Hyper-V VM.

Celery said:

I use Hyper-V, but I haven't used Disk2vhd myself, so I asked ChatGPT for some suggestions:



The screenshot below is from my Hyper-V virtual machine.

bootmgfw.efi is the Windows Boot Manager EFI application, normally located at \EFI\Microsoft\Boot\bootmgfw.efi on the EFI system partition.

The typical Windows UEFI boot sequence is:

UEFI firmware → NVRAM boot entry → bootmgfw.efi (reads the BCD store) → winload.efi

View attachment 188513

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AmericanPharaoh said:

Hi Tecknot,
To add to Celery's excellent suggestion about gathering the diskpart layout, the reason you are seeing this error usually comes down to how Disk2vhd captures partitions.
For a Generation 2 (UEFI) virtual machine to boot, the .vhdx file must contain both your primary operating system partition (C:) and the hidden EFI System Partition (ESP). If you only selected the C: drive checkbox when running Disk2vhd, the VM will have no bootloader, causing Hyper-V to fail over to a network boot (PXE over IPv4).
Once you are able to boot to a Windows ISO, open the Command Prompt (Shift + F10), and run the diskpart commands Celery listed; look closely at the volumes. Depending on what you see, here are the paths to fix it:

Path 1: If the EFI partition is entirely missing from the VHDX
If list volume shows only your main OS partition and no 100MB FAT32 partition, you have two choices:
Choice A: Recreate the VHDX (Recommended & Cleanest)
If you still have access to the original physical machine or source system:

1. Run Disk2vhd as Administrator.
2. Make sure to check the box for both the hidden System/EFI partition and the C: volume.
3. Create the new .vhdx and attach it to your Hyper-V VM.

Choice B: Manually carve out an EFI partition inside the VM
If you cannot re-run Disk2vhd, you can manually shrink your OS partition and create a new bootloader right from the recovery command prompt:

cmd
diskpart
Select disk 0.
list partition
Select partition X (select your main Windows OS partition number).
shrink desired=100
Create partition EFI
format quick fs=fat32 label="System"
assign letter=S
exit

Use code with caution.

Then, apply the boot files to the newly created partition (assuming your Windows OS volume is currently assigned letter C in WinRE):

cmd
bcdboot C:\Windows /s S: /f UEFI
Use code with caution.


Path 2: If the EFI partition IS present but corrupted
If diskpart shows the FAT32 system partition is there, the boot configuration data (BCD) just needs to be rebuilt. Assign a letter to that FAT32 volume inside diskpart (e.g., assign letter=S), exit diskpart, and run:

cmd
bcdboot C:\Windows /s S: /f UEFI
Use code with caution.


Quick setting to check in Hyper-V
Sometimes, a newly converted physical-to-virtual (P2V) image will choke on Hyper-V's default security configuration. Go to your VM's settings in Hyper-V Manager, click on Security, and try unchecking Enable Secure Boot to see if it allows the OS to start loading.
Let us know what your diskpart layout looks like, and we can narrow down the exact commands you need!

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tecknot said:

So, still stuck.....

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tecknot said:

Hi Bree,

I tried making a new VM this time with Gen 1. I ran it and got this:

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tecknot said:

How do I know if the VM was created as MBR or GPT?

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