There is a common misconception that formatting a hard drive physically removes all the data from the drive. This is not the case. In general, when a disk is formatted, the pointers to all files on the disk are erased. The files themselves still remain. This is the case in windows even if you do not select "quick format". The quick format option omits the scan for bad sectors. The deletion of files is limited to the removal of the pointers to the files on disk with both types of formats. In order to fully delete all files on a hard drive, data must be written over the entire surface of the disk. Utilities for performing this can be obtained from the individual hard drive manufacturer of the drive in question.