Although lost photos, which are caused by common reasons like deleting or formatting, in hard disk, memory card, memory stick and USB flash disk will not disappear immediately from storage devices, they will never be protected by operating system. No matter what kind of data users put again into these storage devices, lost photos which have not completely disappeared may be overwritten. In this case, users can never fully recover lost photos by using photo recovery software. Therefore, if users want to insure integrity of photo recovery as much as possible, it is vital to prevent lost photos from being overwritten.
 
There are three main measures:
 1. Immediately stop operating storage device where lost photos were.
 2. Install data recovery software into the partition that has no photo recovery operation.
 3. Save recovered photos into other space except original storage device (For example, users can save photos which are recovered from partition D into partition C, partition E, partition F or other partitions except partition D or save recovered photos to external storage devices; photos recovered from external storage devices like memory card, memory stick and USB flash disk can be saved to any local disk   location that will not be operated).