The pen drive data is shortcut and not visible..

Some times the data of usb drive in not visible and it looks like the shortcut and your dont want to format the pendrive and want to recover the usb drive data.  then u can do this process..

If you did not want format your flash drive, then check whether the files are not in

hidden mode.

Click on "Start" -->Run-->type cmd and click on OK.

Here I assume my  pendrive as G:

Enter this command.

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

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

Now check for your files in Pen Drive.