exporting vhd not allowing us to boot up via vhdx in hyper v

Hello @Tyler Tomayko

You can try this steps for fix the Missing boot files issue.

1.Create a New Temporary VM
Open Hyper‑V Manager.

1. Select New → Virtual Machine.
2. Choose the correct VM Generation:
   • Generation 1 → if disk uses MBR
   • Generation 2 → if disk uses GPT/UEFI
3. Complete the wizard without attaching any disk.

2.Attach the Exported VHD/VHDX

1. Right‑click the new VM → Settings.
2. Under storage controllers:
   • IDE Controller → Gen 1
   • SCSI Controller → Gen 2
3. Attach your 127GB VHD/VHDX.
4. Also attach a Windows installation ISO under DVD Drive.

3.Boot into Windows Recovery

1. Start the VM.
2. When the Windows Setup screen appears: Repair your computer → Troubleshoot → Command Prompt.

4.Identify Disk & Partitions : Run the following

1.diskpart

2.list disk

3.sel disk 0

4.list vol

5.exit

Identify:

• EFI partition (FAT32, ~100–500MB) → Gen 2
• System Reserved (NTFS, ~350–550MB) → Gen 1
• OS partition (largest volume)

5.Repair the Boot Loader

Gen 1 VM

1.bootrec /fixmbr
2.bootrec /fixboot

If /fixboot gives “Access denied”, use: (bcdboot C:\Windows /s C: /f BIOS)

3.bootrec /scanos

4.bootrec /rebuildbcd

If its a Gen 2 VM:

• diskpart
• sel disk 0
• list vol
• sel vol <EFI volume number>
• assign letter=Z
• exit

Rebuild the UEFI files
bcdboot C:\Windows /s Z: /f UEFI

6.Run the file system repair using - chkdsk C: /f

7.Remove ISO & Reboot

• Shut down the VM.
• Remove the ISO from the DVD drive.
• Start the VM normally.

8. Run on the Hyper‑V host:

Repair-VHD -Path "D:\Path\Disk.vhdx"

These steps resolve issues caused by missing boot files, corrupted EFI/MBR, mismatched VM generation, or VHD/VHDX metadata issues.

If the issue still persists please revert back with the error message or snip for reference.

Thanks,
Manish

127GB - hyper v manager - machine wont boot