Free online VHDX to VHD converter

Some older hypervisors, backup programs, and virtual appliances accept .vhd files but reject .vhdx. Converting the image changes its virtual-disk container so it can be attached to software that requires VHD without reinstalling the guest operating system.

What the VHDX format is

VHDX is Microsoft’s virtual hard disk format introduced with Windows 8 and Windows Server 2012 for Hyper-V. It stores virtual machine operating-system disks and data disks in files ending in .vhdx; Hyper-V uses it as the default format on current Windows versions.

VHDX supports virtual disks up to 64 TB, larger sector and block configurations, improved metadata protection, and logging designed to reduce corruption after an unexpected power loss. Windows can create, attach, and mount VHDX images through Hyper-V, Disk Management, and PowerShell.

What the VHD format is

VHD is the older Microsoft virtual hard disk format used by Microsoft Virtual PC, earlier Hyper-V versions, legacy backup software, and virtualization products that implement the VHD specification. Its files use the .vhd extension.

VHD supports fixed-size, dynamically expanding, and differencing disks and remains useful when a target platform does not recognize VHDX. Its practical maximum capacity is approximately 2 TB, so a VHDX containing a larger virtual disk cannot be converted to one standard VHD without first reducing the disk capacity or using a target-specific alternative.

Convert with Hyper-V Manager

1. Shut down the virtual machine and ensure the source disk is not attached to a running VM. Keep a backup of the original image.
2. Open Hyper-V Manager and choose Action → Edit Disk.
3. Browse to the source .vhdx file and select Convert.
4. Choose VHD as the destination format.
5. Select Fixed size or Dynamically expanding, specify a new path ending in .vhd, and complete the wizard.
6. Attach the new disk to a test VM and verify its partitions, files, boot mode, controller, and boot order before removing the source.

Convert with PowerShell

On Windows with the Hyper-V PowerShell module installed, open an elevated PowerShell window and run:

Convert-VHD -Path "D:\VM\disk.vhdx" -DestinationPath "D:\VM\disk.vhd" -VHDType Dynamic

Replace both paths with the actual locations. Use -VHDType Fixed for a fixed-size destination. The destination file must not already exist, and the account running the command needs read permission for the source and write permission for the destination folder. Conversion does not reduce the guest filesystem or automatically reclaim unused space.

Other conversion options

You can convert the file on 101convert.com for free without installing software: upload the VHDX, select VHD, start the conversion, and download the result. Upload only disks whose contents are appropriate for the service’s storage and retention terms; virtual disks commonly contain credentials, personal data, and proprietary files. Large images may also be limited by upload time or service file-size limits.

QEMU users can use qemu-img as an alternative:

qemu-img convert -f vhdx -O vpc source.vhdx destination.vhd

QEMU names its VHD output driver vpc. Test the resulting image on the target hypervisor, because boot behavior, sector geometry, controller support, and differencing-disk handling can vary between virtualization platforms.

Compatibility and data caveats

• The conversion changes the virtual-disk container, not the guest operating system, partition table, filesystem, or files. It does not convert a physical installation into a different operating system.
• A checkpoint normally uses a differencing .avhdx child linked to a parent .vhdx. Do not convert or move one file from a checkpoint chain and discard its parents; merge or remove the checkpoint through Hyper-V, or preserve the complete parent chain required by the target software.
• If the source disk is larger than the VHD capacity limit, shrink the guest partitions and filesystem first, then reduce the virtual disk’s maximum size with a suitable disk-management tool. A conversion command alone does not perform this operation.
• A dynamically expanding destination grows as data is written but does not automatically shrink to the amount of used data. To reduce its physical size, zero unused guest space and compact the image with the relevant virtualization utility.
• VHD lacks VHDX features such as its larger capacity limit and enhanced metadata protection. Applications that depend on VHDX-specific sector, resiliency, or checkpoint behavior may not work after conversion.
• A Generation 2 Hyper-V VM boots with UEFI, while older VMs may use BIOS. If the converted disk does not boot, check the VM generation, firmware mode, Secure Boot setting, controller type, and boot order.
• Retain the original VHDX until the converted disk has been mounted or booted successfully and important files have been verified.