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.
How to open 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. For a step-by-step walkthrough, see how to open a .vhd file.
Windows
- Hyper-V
- Disk Management (mount)
- VirtualBox
macOS
- VirtualBox
- qemu-img (convert)
Linux
- qemu / qemu-img
- VirtualBox
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.
.vhd file signature (magic bytes)
Programs recognise a .vhd file by the bytes at the start of the file, not by its name. These are the signatures for VHD. For a full breakdown, see the VHD file signature page.
| Hex signature | Offset | Note |
|---|---|---|
| 63 6F 6E 65 63 74 69 78 | 0 | '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
Details on this page were checked against authoritative references: