Data loss due to misoperation during system installation

Case:
After the reinstallation system is over, I found that the data in the hard disk was gone, and the partitions have changed. It turned out to be 4 districts. Now it is 3 districts. There are some personal data that is more important to recover the data.

Solution:
The detection of engineers is misunderstanding of data loss.In order to ensure the safety of the source disk, no operation is done to the source disk.So the engineer used a professional PC3000-UDMA to mirrize the hard disk, and then used professional data to recover software to analyze the mirror files, and the final data recovered successfully.