What is "vhd"

VHD may refer to:

• Video High Density, a videodisc format
• VHD (file format), or Virtual Hard Disk file format, a disk image format used by Microsoft Virtual PC
• Volumetric Haptic Display
• Rabbit haemorrhagic disease, also known as Viral Haemorrhagic Disease
• Valvular heart disease, a disease involving one or more of the four valves of the heart

VHD (Virtual Hard Disk) is a file format which represents a virtual hard disk drive (HDD). It may contain what is found on a physical HDD, such as disk partitions and a file system, which in turn can contain files and folders. It is typically used as the hard disk of a virtual machine.

The format was created by Connectix for their Virtual PC product, known as Microsoft Virtual PC since Microsoft acquired Connectix in 2003.

Since June 2005, Microsoft has made the VHD Image Format Specification available to third parties under the Microsoft Open Specification Promise.