Pen drive show empty even when data exists

Check if the files are not in hidden mode. 

Click on "Start" -->Run --> Type cmd and press Enter. 

Here I assume your pendrive drive letter as G: 

Enter this command. 

attrib -h -r -s /s /d g:\*.* --> Press Enter 

You can copy the above command --> Right-click in the Command Prompt and 

paste it. 

Note : Replace the letter g with your pen drive letter. 

Now check your pen drive for the files. 

Good Luck