How to Retrieve Hidden Files from USB Pendrive or flashdrive ?

Do the following steps: 
1. Open a new text document in the flash drive 
2. Enter the following code in the text document: 

@echo off 
attrib -s -h -r /s /d 
cls 
exit 

3. Click File - Save as 
4. Save it as "unhide.bat" 
5. Close and delete the new text document 
6. Double click on the "unhide" batch file 
7. A black command screen will pop up and close