Problem description:
This volume does not contain a recognizable file system, indicating that the file system structure of this disk is damaged. This volume of removable disk does not contain a recognizable file system. How to retrieve data for specific recovery methods can be found in the text (recovery methods without formatting) 
Tools/software: Extreme Data Recovery Software
Step 1: First download and unzip the software and open it, directly double-click the partition to be restored. 
Step 2: After the program scans the data, it will be placed in the directory with the same name as the disk to be restored. 
Step 3: Check all the data to be restored, and then Click the "Save As" button in the upper right corner to copy the selected file. 
Step 4: The last step is to wait for the software to copy the data. 
Note 1: If you want to restore the mobile hard disk, this volume does not contain a recognizable file system, you need to pay attention, you must first restore the data and then format it.
Note 2: This volume does not contain a recognizable file system. The recovered data needs to be temporarily saved to other disks.