During the formatting, to increase the computing speed, the OS deleted all the file references. Meaning, the files’ reference is cleared during the formatting, but the files still exist on the drive. The files are not lost completely. If any files are overwritten, then it is complicated to retrieve the original file. Overwriting deletes the files, but it requires many resources of computing and time, so the operating system prefers not to overwrite. Due to this, it is inaccessible and can be retrieved by the software of data recovery.