Whenever, the authors want to store some data for future use, they store it on the hard disk. Hard disk drive is a data storage device used for storing and retrieving digital information. Data is stored on the hard disk in 4096 bytes of block containing 8 512 byte sectors each. Just like physical hard drives, VHD files are at risk for corruption, accidental deletion, virus attacks and other causes of data loss. As such, the ability to recover data from a VHD image can be very valuable.