What is a .vhd file?
Virtual Hard Disk · Disk image · Connectix / Microsoft · 2003
A .vhd file is a Virtual Hard Disk: a single file that acts like a physical hard drive for a virtual machine. Windows uses it for Hyper-V, and can even boot from or mount a VHD directly.
What is a .vhd file used for?
A VHD contains a whole disk, partitions and filesystem, inside one file marked by the string conectix in its header and footer. Windows can mount a VHD as a drive letter through Disk Management.
Its successor VHDX is more robust and supports larger disks. VirtualBox and other hypervisors also read VHD.
What opens a .vhd file?
The .vhd format opens in the following apps, grouped by operating system. If one app does not work, try another from the same list.
Windows
- Hyper-V
- Disk Management (mount)
- VirtualBox
macOS
- VirtualBox
- qemu-img (convert)
Linux
- qemu / qemu-img
- VirtualBox
Open a .vhd file step by step
- Confirm the file really is a .vhd. Drop it into the WhatFileType identifier, which reads its signature in your browser without uploading anything.
- On Windows, open it with Hyper-V or Disk Management (mount).
- On Mac, use VirtualBox or qemu-img (convert).
- On Linux, try qemu / qemu-img or VirtualBox.
- Still stuck? Convert the .vhd to vhdx, which opens more widely.
Why can't I open my .vhd file?
Almost always because no installed app understands VHD. Install one of the apps above, or convert the file to a format your existing software already reads. If double-clicking opens the wrong program instead of nothing at all, the file association is set to the wrong app rather than the file being broken.
The other possibility is that the file is not really a .vhd at all. Drop it into the file identifier to check it by its bytes instead of its name. Nothing is uploaded.
How to convert a .vhd file
You can convert a .vhd file to vhdx, vmdk, img using a conversion tool or the export menu of an app that opens it.
What is the .vhd file signature (magic bytes)?
A .vhd file starts with the hex bytes 63 6F 6E 65 63 74 69 78, which read as conectix in ASCII. Programs identify VHD by those bytes, not by the filename, so a renamed file still gives itself away.
These are the documented signatures for VHD. For a full breakdown, see the VHD (virtual disk) file signature page.
| Hex signature | Offset | ASCII | Note |
|---|---|---|---|
| 63 6F 6E 65 63 74 69 78 | 0 | conectix | 'conectix' (footer copy is at end of file) |
See the full magic-numbers reference for every format.
Frequently asked questions
What is a .vhd file?
A .vhd file is a Virtual Hard Disk: a single file that acts like a physical hard drive for a virtual machine. Windows uses it for Hyper-V, and can even boot from or mount a VHD directly.
How do I open a VHD file?
On Windows, right-click it or use Disk Management to mount it as a drive. Hyper-V and VirtualBox can boot it as a virtual machine.
What is the difference between VHD and VHDX?
VHDX is the newer Hyper-V format: it supports much larger disks and resists corruption from power loss. VHD is older and more widely compatible.
Can I mount a VHD as a drive?
Yes, on Windows. Open Disk Management, choose Attach VHD, and it appears as a normal drive letter.
Comparisons
Related formats
Sources
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